Carbon materials: surface chemistry and biomedical applications III

Resume : Nanodiamond particles can be used for a variety of biomedical applications due to their unique properties. This includes imaging using luminescent lattice defects, drug delivery and the application as material in bone implants and other biocompatible materials. However, most of these applications require a stable dispersion of the nanodiamond particles in physiological media. Typical diamond materials show a very strong tendency to agglomerate and surface modification is needed to establish suitable moieties. Here we report on the functionalization of nanodiamond with saccharide motifs and ionic species which enable the formation of stable colloidal dispersions of nanodiamond also in cell culture media containing salts and serum proteins. The effect of the surface functionalization on the long-term stability, overall particles size and charge as well as on the biocompatibility will be discussed. This project has received funding from the Volkswagen foundation in the framework of the initiative “Integration of Molecular Components in Functional Macroscopic Systems”, project Az. 88 393.

Resume : In this work, we investigated the interaction of graphene oxide (GO) with Phe-Phe (FF) and Tyr-Tyr (YY), to fabricate a hybrid peptide-GO assembly with multifaceted features. The 2-Dimensional GO nanosheets, due to their high surface-to-volume ratio and the richness of oxygen-containing moieties (including carboxyl, hydroxyls and epoxide groups) represent an ideal nanoplatform for drug delivery applications [1]. The integration of GO with homo-aromatic dipeptides, which are able to self-assembly into ordered structures such as nanotubes and nanowires [2], offers unique potentialities at the biointerface because of the increased biocompatibility of the hybrid system and, remarkably, for the capability to load/protect a cargo into the peptide nanocontainers. The peptide-GO assemblies were scrutinised spectroscopically (UV-visible, fluorescence and circular dichroism) and microscopically (atomic force microscopy and confocal microscopy). Quartz crystal microbalance with dissipation monitoring was used for real-time acoustic sensing of the interaction with supported lipid bilayers, used as model cell membranes. Promising results of cellular uptake in neuroblastoma cells were measured by confocal microscopy for the peptide-GO assemblies loaded with the anticancer drug doxorubicine. [1] Consiglio, G. et al., 2017, J Coll Interface Sci, 506, 532. [2] Reches, M., & Gazit, E., 2003. Science, 300, 625.

Resume : Benefiting from their unique physicochemical properties, graphene derivatives have attracted great attention in biomedicine. However, how graphene oxide (GO) derivatives might affect the cell cycle has been rarely studied. Herein, a GO derivative was fabricated by functionalization of GO with polyethylene glycol (PEG) and polyethylenimine (PEI), and its cytotoxic mechanism was investigated in-depth. It was found that our obtained GO-PEG-PEI nanosheets, not the cytotoxic coating polymer PEI, could induce defect in S phase of the mammalian cell cycle, resulting in decreased DNA synthesis, S phase arrest, and abnormal cytoskeleton structure. Further analysis demonstrated that this damaging effect on S phase could be detected in all five tested mammalian cell lines. Even at seemingly safe concentration (~90% cells viable), GO-PEG-PEI could still induce S phase defect. Detailed investigations revealed that GO-PEG-PEI could cause genomic DNA damage, activating the intra-S-phase checkpoint control via both the ATM and the ATR signaling pathways. Our work unveils the signaling pathways involved in the interaction of GO-PEG-PEI with mammalian cells, and highlights the necessity and importance of comprehensive investigations of the effects of nanomaterials on cellular pathways, such as the cell cycle in this case, even for those with seemingly little/low cytotoxicity during preliminary evaluations. Our work also highlights the critical roles of surface chemistry in biological effects of nanomaterials and the rational design of GO derivatives for biomedical applications.

Resume : Radicals production seems to play a major role in innovative applications of nanodiamonds. Indeed, the possibility to use hydrogenated diamond surface as a solid source for the production of solvated electrons usable for CO2 reduction was evidenced by the pioneer work of Hamers et al. [1] and our previous work showed that hydrogenated detonation nanodiamonds can induce an in vitro radiosensitizing effect under gamma irradiation, in which hydroxyl radicals are usually involved [2]. The present study aims to quantify hydroxyl radicals and solvated electrons produced by aqueous suspensions of detonation nanodiamonds of different concentrations under irradiation. The quantification was achieved in solution using a protocol based on coumarin fluorescence [3]. Our first work demonstrated the overproduction of hydroxyl radicals for hydrogenated nanodiamonds under irradiation by X-rays compared to oxidized particles [4]. The present study investigates the effect of the surface chemistry on the overproduction of hydroxyl radicals considering hydrogenated, oxidized and surface graphitized nanodiamonds prepared from the same source. Two irradiation energies were used: X-rays (17.5 keV) or gamma rays (1.17 MeV). The protocol was then adapted to quantify solvated electrons. This overproduction of hydroxyl radicals and solvated electrons will be discussed considering the possible role of the surface chemistry, the colloidal stability of aqueous suspensions, the diamond core and the water interface with nanodiamonds. References [1] R. J. Hamers, J. A. Bandy, D. Zhu, L. Zhang, Faraday Discuss 172 (2014) 397. [2] R. Grall, H. A. Girard, L. Saad, T. Petit, C. Gesset, M. Combis-Schlumberger, V. Paget, J. Delic, J. C. Arnault, S. Chevillard, Biomaterials 61 (2015) 290. [3] C. Sicard-Roselli, E. Brun, M. Gilles, G. Baldacchino, C. Kelsey, H. McQuaid, C. Polin, N. Wardlow, F. Currell, Small 2014, 10, 3338. [4] M. Kurzyp, H. A. Girard, Y. Cheref, E. Brun, C. Sicard-Roselli, S. Saada, J. C. Arnault, Chem. Commun., 53 (2017) 1237.

Resume : After discovery of Graphene in 2004, the interest to the two dimensional (2D) materials has raised due to their outstanding properties arising from the field of both experimental and theoretical studies. These types of materials have inherent large surface-to-volume ratios, which makes them to be considered as molecular diagnostics, DNA sequencing and biosensors. At the same time, the track and detection of amino acids will provide detection of several diseases by using biosensors. As an example, it is possible to diagnosis of malaria disease by detecting Histedine and diagnosis of several cancer types and Parkinson’s disease by detecting Leucine. However the binding energies of the biomolecules on the graphene are weak. In order to increase the binding, functionalization the 2D materials with atoms is required. We have investigated the interaction between Histidine /Leucine molecules with Ti/C functionalized graphene. The results indicate that decorating the graphene with the atoms (Ti,C) significantly affect the binding mechanism, electronic properties and adsorption states.

Resume : Carbon-based materials in both planar and nanostructure form are very attractive platforms for fundamental science and practical application because the great strength of C-C bonds leads to extraordinary chemical stability. The functionalization of carbon materials with organic molecules and molecular ligands provides a way to tune the charge, hydrophobic/hydrophilic character, and other physicochemical properties. In this talk I will summarize some of the methods used to functionalize diamond and other carbon-based materials, and the impact of this functionalization on properties such as charge state and aggregation behavior, which are critical for understanding the behavior of carbon-based nanomaterials in complex environments.

Resume : In this study, ordered mesoporous carbon (OMC) was prepared for the CO2 sorption following the soft-templating method using resorcinol-formaldehyde resin as precursor and triblock copolymer F127 as a template. Guanidine presents a strong affinity for CO2 and was incorporated in the OMC via a customized protocol involving several steps: oxidation, acylation and amidation. The ordered mesoporous architecture was characterized by transmission electron microscopy (TEM) and nitrogen adsorption/desorption measurements before and after the functionalization, whereas the surface chemistry by thermogravimetric analysis (TGA) and temperature programmed desorption (TPD) coupled with mass spectrometry. The adsorption properties of the as-obtained “guanidine-OMC” platforms for the CO2 molecules were also qualitatively determined, in view of the envisioned application. As main results of this study, by using a combined analysis approach based on the techniques mentioned above, the quantification of the guanidine loading on the carbon surface was determined as well as the stability of the molecules on the surface in specific environmental conditions. In addition, a first and very useful insight on their localization on the carbon surface was indirectly obtained by analyzing by TEM the hybrid materials subsequently impregnated with metallic salts which have the property to specifically nucleate at the guanidine positions for forming cluster or metallic particles.

Resume : A coconut-shell-based carbon was activated with KOH and three methods of ammonia modification were used to prepare nitrogen-containing activated carbon of high surface area. Thus, a cost-effective, scalable, and metal-free electrocatalyst was developed for use in oxygen reduction reaction (ORR). Elemental analysis, X-ray photoelectron spectroscopy, Scanning electron microscopy and nitrogen adsorption have been used to analyze the physicochemical properties of activated carbons. The electrocatalytic performance of activated carbons was investigated with respect to ORR using cyclic voltammetry and linear sweep voltammetry in an alkaline electrolyte. The results indicate that the species distribution of nitrogen-containing groups was significantly affected by the method and temperature of ammonia modification. These factors consequently determined the electrocatalytic performance of the modified activated carbons. When the nitrogen-containing activated carbon was prepared by methods I and II at 950 °C, it exhibited an electrocatalytic activity toward ORR that was comparable to that of commercial 20% Pt/C catalyst in terms of onset potential and limiting current density. Moreover, they catalyzed ORR approximately in a four-electron pathway and showed good tolerance toward methanol crossover. In addition, we investigated the influence of various nitrogen-containing species on the electrocatalytic performance

Resume : Our aim was to tune the photocatalytic and gas sensing properties of various carbon nanostructures by coating them with atomic layer deposition (ALD) grown oxide nanofilms and nanoparticles. As substrates, OH functionalized fullerene (C60-OH), OH functionalized carbon nanotubes, graphene oxide (GO) synthesized with the improved Hummers method, carbon nanospheres obtained hydrothermally as well as carbon aerogels were used. Onto them, TiO2, ZnO and Al2O3 thin films and nanoparticles were deposited by ALD. The C60-TiO2 composite was the first example of ALD prepared single molecule fullerene/oxide composite. The other depositions also meant the extension of the use of the ALD onto these important substrates. The photocatalytic and gas sensing of the as-obtained nanocomposites was investigated. Unexpectedly, amorphous TiO2 grown by ALD had photocatalytic activity on these substrates - usually TiO2 is considered to have photocatalytic activity only in crystalline state. The gas sensing of the substrates was considerably modified by the deposited oxide layers and multilayers.

Resume : Fluorinated carbon materials are of high importance in many fields of science and technology including chemistry, biochemistry and materials science. Fluorination is often used to enhance the hydrophobicity of carbon materials. Probably the most prominent example is PTFE, better known as Teflon. The poor wetting properties of perfluorinated carbon compounds can be traced back to the very weak interaction with water at the molecular level. On a first glance this might come as a surprise: F is the most electronegative element, thus C-F bonds are highly polar and commonly polar surfaces are associated with hydrophilic behavior. This seeming contradiction is known as polar hydrophobicity [1]. Using fluorinated diamond surfaces as model systems we show that the polar hydrophobicity of perfluorinated materials is caused by the high packing density of C-F dipoles and that it is a very unique phenomenon peculiar to this class of materials [2]. Although our conclusions were derived from a combination of ab initio DFT calculations and classical molecular dynamics simulations, the polar hydrophobicity can also be understood in terms of a simple electrostatic model based on point charges. Moreover, we will discuss under which conditions the polar C-F bonds can indeed act as reasonably strong H-bond acceptors and hence can lead to hydrophilic behavior of partially fluorinated carbons. The concepts derived for fluorinated diamond surfaces can be easily transferred to fluorinated molecules as we will demonstrate. [1] J. C. Biffinger, H. W. Kim, and S. G. DiMagno, ChemBioChem 5, 622-627 (2004). [2] L. Mayrhofer, G. Moras, N. Mulakaluri, S. Rajagopalan, P. A. Stevens, and M. Moseler, J. Am. Chem. Soc. 138, 4018?4028 (2016).

Resume : Interleukin-6 (IL-6) is a multi-functional cytokine with a wide range of biological activities such as regulation of the immune system and generation of acute phase reactions. IL-6 also plays a key role in metabolism during exercise. IL-6 is predominantly produced within the working skeletal muscles during exercise. IL-6 circulation levels were also found to increase in response to acute exercise in young males and can be modulated by acute bout of high-intensity intermittent exercise in comparison to continuous moderate-intensity exercise (MOD). Currently, ELISA and western blot is the staple for detection of IL-6, requiring substantial time, machinery, high cost and specialized manpower training. The presented Graphene Oxide-based amperometric sensor has the advantage of cheap, simple, real-time yet sensitive. However, the coverage of mono-layered Graphene Oxide flake on SiO2 substrate is limited to ca. 90% due to rinsing and unwanted cross-linking of 3-AminoPropylTriEthoxy Silane(APTES) adhesion layer. APTES silanization is commonly employed to coat a mono-layer of GO on SiO2 via electrostatic attraction. Although complete mono-layered APTES coverage can be obtained via time-consuming APTES Chemical Vapour Deposition (CVD) growth, the rinsing step cannot be removed from procedure. This incomplete coverage leads to less available surface area, and more importantly, low sheet transconductance that limits sensitivity of the sensor. In our work, we demonstrate that carbon can be deposited on edges of Graphene Oxide flakes in an ethanol CVD environment, due to lower chemical potential at the flake edges. This deposition increases the area coverage of GO flakes on substrate and improves the transconductance and sensitivity of sensor. Finally, the transducer is fabricated into a liquid-gated biosensor and the detection window on IL-6 is presented. Our method provides a highly conductive carbon-based transducer that can be used to make cheap, simple, real-time yet sensitive amperometric sensors for IL-6.

Resume : An appropriate candidate in sensing systems (as an electrode) is graphene [1] or other 2D materials [2]. The large surface area and superior electrical conductivity of graphene make it an excellent «electron wire» between the redox centres of an interested molecule and the electrode’s surface. Owing to the extraordinary electronic transport property and high electrocatalytic activity of graphene, the electrochemical reactions of analyte are greatly promoted on the graphene film, resulting in enhanced voltammetric response. Graphene is now a more mature technology, it can be produced in a cost-effective way, in large scale and in a short time, it shows good biocompatibility, and the source material is abundant and inexpensive [3]. Graphene is extremely stable to the environmental conditions and does not degrade with time, which makes it an ideal material for stable sensor performance. It also has a range of surface chemistry which can be used to modify the graphene surface [4,5], and make it amenable to detecting different (bio)markers. Thus, graphene is a promising candidate of advanced electrode materials which has found its way into a wide variety of sensing schemes [6]. Herein we report new laser-assisted patterning of graphene films which can selectively enhance certain sensory and (opto)electronic capabilities of graphene-based devices and can offer its progress of the next generation for energy storage, photonics, and bioelectronics [7,8]. Basically, device's advanced multifunctionality (sensitivity, selectivity, reactivity) is driven by exerting the periodicity and forming active centers on the surface of graphene electrodes. Therefore, we represent new approach of multilayer graphene (MLG) patterning employing nonlinear laser lithography (NLL) which is contamination-free, rapid and low-cost pattern replication technique. Via patterning we demonstrate tuning of chemical and electro-optical properties of MLG due to laser power adjustment (310 – 380 mW). We control the hydrophobic/hydrophilic properties which define multifunctionality of graphene-enabled devices due to the graphene surface (dis)organizing, and consequently, a formation of reactive oxygen-based functional groups. Distinct graphene structure alignment (which prevents defects appearance) assisting by strongest laser power (380 mW) contributes in patterned MLG electro-optical changes (sheet resistance decreasing and optical transmittance enhancement) as well. In conclusion, we discuss the great promise of fabricated devices with supercapacitor and battery designs by using as an electrically reconfigurable medium NLL-assisted graphene patterning. The patterned MLG-based supercapacitor testing results reveal two times transmittance value rising (in comparison with MLG-based supercapacitor) caused by light interaction with patterned structures where its thickness is reduced. Meanwhile the patterned MLG-based battery indicates long-life viability (500 charging/discharging cycles) with 0.01% capacity-loss per cycle. We anticipate, proposed NLL-assisted approach for MLG patterning demonstrates a new avenue to advance graphene for multifunctional device engineering particularly in energy storage, wearable electronics, and biosensorics. [1] Tapaszto, L.; Dobrik, G.; Lambin, P.; Biro, L.P. Tailoring the atomic structure of graphene nanoribbons by scanning tunneling microscope lithography. Nat. Nanotechnol. 2008, 3, 397. [2] Zhang, L.; Diao, S.; Nie, Y.; Yan, K.; Liu, N.; Dai, B.; Xie, Q.; Reina, A.; Kong, J.; Liu, Z. Photocatalytic patterning and modification of graphene. J. Am. Chem. Soc. 2011, 133, 2706. [3] Jiao, L.; Zhang, L.; Wang, X.; Diankov, G.; Dai, H. Narrow graphene nanoribbons from carbon nanotubes. Nature 2009, 458, 877. [4] Kosynkin, D.V.; Higginbotham, A.L.; Sinitskii, A.; Lomeda, J.R.; Dimiev, A.; Price, B.K.; Tour, J.M. Longitudinal unzipping of carbon nanotubes to form graphene nanoribbons. Nature 2009, 458, 872. [5] Wei, Z.; Qiang, Z.; Meng-Qiang, Z.; Luise Theil, K. Direct writing on graphene «paper» by manipulating electrons as «invisible ink». Nanotechnol. 2013, 24, 275301. [6] Feng, J.; Li, W.; Qian, X.; Qi, J.; Qi, L.; Li, J. Patterning of graphene. Nanoscale 2012, 4, 4883. [7] Choi, W.; Lahiri, I.; Seelaboyina, R.; Kang, Y.S. Synthesis of graphene and its applications: A review. Crit. Rev. in Solid State Mater. Sci. 2010, 35, 52. [8] Shao, Y.; Wang, J.; Wu, H.; Liu, J.; Aksay, I.A.; Lin, Y. Graphene based electrochemical sensors and biosensors: A review. Electroanal. 2010, 22, 1027.

Resume : Diabetes has become one of the biggest global threats to human health, and diabetes is closely associated to blood glucose levels. Therefore, It is vitally important for diabetes diagnostics to precisely monitor glucose level in blood. A facile and scalable in situ synthesis strategy is developed to fabricate carbon encapsulated NiO nanoparticles homogeneously embedded in two dimensional (2D) porous graphitic carbon nanosheets (NiO@C@PGC) as high performance nonenzymatic glucose detection in human serum. With aid of the water-soluble NaCl cube crystals, 2D Ni@C@PGC nanosheets can be in situ synthesized by using the Ni(NO3)2?6H2O and citric acid as the metal and carbon source, respectively. After annealing under air, the Ni@C@PGC nanosheets can be converted to NiO@C@PGC nanosheets. In the constructed architecture, the thin carbon shells can avoid the direct exposure of encapsulated NiO to the electrolyte and preserve the structural and interfacial stabilization of NiO nanoparticles. Meanwhile, the flexible and conductive PGC nanosheets can accommodate the mechanical stress induced by the volume change of embedded NiO@C nanoparticles as well as inhibit the aggregation of NiO nanoparticles and thus maintain the structural and electrical integrity of the NiO@C@PGC modified electrode during high performance nonenzymatic glucose detection process. Cyclic voltammetric (CV) study showed NiO@C@PGC nanosheets indicated better electrocatalytic activity toward glucose oxidation as compared to Ni@C@PGC nanosheets. Amperometric study indicated the glucose sensor displayed high performance, offering a low detection limit, a high sensitivity, and a wide linear range. Importantly, good reproducibility, long-time stability, and excellent selectivity were obtained within the as-fabricated glucose sensor. Furthermore, the constructed high-performance sensor was utilized to monitor the glucose levels in human serum, and satisfactory results were obtained. It demonstrated the NiO@C@PGC nanosheets can be used as a good electrochemical sensing material in practical biological applications.

Resume : Carbon nanofiber (CNF) carrying metal- or metal oxide nanoparticles (MNPs) are widely used as a transducer for non-enzymatic electrochemical sensing of clinical biomarkers, e.g. H2O2 and NADH. Uniform distribution of the MNPs along CNFs and addressable sensing area are favorable for maximizing sensitivity and facilitating device integration. We developed a novel strategy to fabricate CNF electrode and simultaneously induce the formation of MNPs in CNFs. Here, an electrospun nanofiber mat made from the mixture of solvent soluble polyimide and metal salt was fabricated on ITO electrode and served as a precursor substrate to generate addressable CNF/MNPs electrodse via laser-assisted carbonization and MNP formation. Our investigation first focused on maintaining the integrity of CNF electrodes, which can be realized through proper density of fiber mat and laser conditions. The fiber substrate with high density significantly maintains the desired CNF structure and offers better electrochemical behavior. The final morphology of CNF electrodes and carbon quality are largely governed by the power and speed of the laser as indicated by SEM and Raman spectroscopy, respectively. Characterization of MNPs with respect to their chemistry and electrochemical performance towards the aforementioned analytes are being investigated. The proposed technique is robust and highly compatible with microsystem integrations, facilitating potential uses of CNFs/MNPs hybrid in biomedical applications.

Resume : New opportunities for chemosensing, biosensing, and plasmonics are offered by graphene-based hybrids. In this contribution, we show graphene coupled to plasmonic nanoparticles (NPs) of gold, silver, aluminum, and gallium, which is functionalized with a variety of biomolecules such as protoporphyrins that plays a key role in numerous biochemical reactions, rhodamine, as a drug model, and functionalized with human fibronectin whose functionality is checked by its response to its antibody monoclonal anti-human fibronectin. The graphene is grown by CVD and then transferred to glass. The various Au, Ag, Al and Ga metal NPs are deposited using sputtering with the characteristic of having a surface plasmon resonance from the visible to the blue and violet. Furthermore, the choice of the above metal NPs is also because of their different work functions covering the range 3.9-5.3 eV with respect to that of graphene of 4.56 eV and, therefore, allowing charge transfer to and from graphene. In response to the direction charge transfer, we discuss the sensing activity of the graphene hybrids. From the fundamental science perspective, the interfacial charge transfer in these hybrid structures is elucidated through extensive characterization. From a technologically relevant perspective, these electronic phenomena present in this new class of hybrid systems are exploited in novel gas- and bio- sensors. We acknowledge the EU project TWINFUSYON. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 692034.

Resume : The selective two-electron oxygen reduction reaction (ORR) for an onsite Fenton oxidation reaction over an integrated aerogel is a promising method for environmental purification. Here, an economic iron-copper-embedded carbon aerogel exhibited high ORR activity. The electron transfer number (n) was 2.9. Indeed, Fe@Fe3C promoted the ORR activity, while Cu enhanced the selectivity of the two-electron ORR. Meanwhile, the simultaneous incorporation of Fe and Cu simultaneously facilitated the sequential Fenton oxidation induced by H2O2. The individual rate constants for ORR and the oxidation reaction successfully revealed the fact that the efficient Fenton oxidation reaction again promotes again the 2-electron O2 reduction pathway. The application of iron-copper-carbon as a cathode in the electro-Fenton process, exhibited efficient total organic carbon (TOC) removal (88-99%) in 240 min for dimethyl phthalate (DMP), imidacloprid (IMI), bisphenol A (BPA) and perfluorooctanoate (PFOA). Moreover, five types of sanitary sewage were successively treated to meet the national discharge standards (chemical oxygen demand (COD)<50 mg L-1) with relatively low specific energy consumption (20‒40 kW•h•(kgCOD)-1) using FeCuC in the heterogeneous EF process.

Resume : Nanomaterials are versatile building blocks for fluorescent biosensors but achieving high selectivity and sensitivity is still a great challenge. We use carbon nanomaterials such as semiconducting single-walled carbon nanotubes (SWCNTs) as building blocks for optical biosensors. SWCNTs fluoresce in the nIR and their optoelectronic properties are very sensitive to changes in the chemical environment. In general, a sensor requires a recognition unit to bind a molecule of interest and typically well-known motifs such as antibodies or aptamers are used. However, these recognition units are large compared to the size of a nanotube, which would result in poor sensitivity. Therefore, we followed a new approach and created new recognition motifs by letting macromolecules such as DNA and peptides directly adsorb and fold on the SWCNT surface. Using this concept, we created different organic phases around SWCNTs and we show that some of them are able to recognize highly important biomolecules. Furthermore, we studied the mechanism of signal transduction and found that conformational changes of the macromolecule change the potential landscape around the SWCNT and consequently exciton diffusion and fluorescence decay pathways. We demonstrate the versatility of this sensor design by imaging small molecules (dopamine), proteins (integrins) and sugars (lipopolysaccharides) in cellular systems. In summary, such sensors are useful tools to image complex biological processes such as chemical communication between cells as well as for biomedical diagnostics.

Resume : Diamondoids are tiny hydrogen-terminated diamond-like cages which can assume a variety of sizes, have tunable optoelectronic properties, and can be chemically modified. Their selective modifications provide functionalization possibilities for binding them to a variety of substances, ranging from molecules to metal surfaces. Due to their variability, diamondoids have the potential to be used in novel nanotechnological applications. Here, we investigate a number of these applications, with a specific focus on biosensing. First, we show that these molecules can form self-assembled monolayers on metallic surfaces and molecular junctions. We next, prove that small diamondoids can form measurable hydrogen bonds to small biomolecules, such as DNA nucleobases. At a next step, we turn to diamondoid-functionalized metal electrodes and calculated the electronic transport across these in order to assess their biosensitivity. For this, different DNA nucleotides were taken, including mutations and epigenetic markers. We have clearly shown, that the diamondoid-electrodes can efficiently distinuigh among these. Our investigations are based on quantum-mechanical calculations and the evaluation of the electronic and quantum transport properties of the diamondoid-based devices. Based on these properties, we will discuss the efficiency and complications of diamondoid-based devices and also reveal the charge transfer process between the DNA nucleotides and the anchoring diamondoid molecules.

Resume : Graphene nanosheets (GS) was prepared via ultrasonic exfoliation of graphite powder in N-methyl-2-pyrrolidone (NMP) with the assistance of sodium citrate. The morphology was characterized by scanning electron microscopy (SEM), and layer number of GS was observed to be about 10-15 using transmission electron microscopy (TEM) and confirmed by atomic force microscopy (AFM). The prepared GS was used as a modifier to modify the glassy carbon electrode（GCE）for the detection of 10-hydroxycamptothecin (10-HCPT) , a natural alkaloid with anti-cancer activity. Then the electrochemical behavior of 10-HCPT was studied using differential pulse voltammetry (DPV). The modification of GS improved the oxidation peak current of 10-HCPT on GCE significantly. The influences of pH value, amount of graphene, accumulation potential and accumulation time on the oxidation peak current of 10-HCPT were studied. Based on the signal amplification of GS, a highly-sensitive analytical platform for 10-HCPT was fabricated. The linear range was from 5.0 to 250.0 μg L-1, and the detection limit was 0.16 μg L-1. This method was used to detect the recovery of 10-HCPT in human urine sample, and satisfactory results were obtained.

Resume : Among the nanomedecine challenges, engineering nanomaterials able to combine imaging and multi-therapies is hugely needed to address issues of a personalized treatment. Further designing biocompatible and remotely responsive nanocomposites has become central in the field of theranostic nanoparticles.[1-5] In that context, a novel class of drug releasing and remotely activated nanocomposites based on carbon-based materials coated with mesoporous silica and loaded with an outstanding level of the anti-tumoral drug doxorubicin (DOX) has been designed. [6] Such nanocomposites are shown able thus to combine drug delivery, phototherapy and imaging, thanks to the carbon based materials. First, carbon nanotubes (CNTs) and graphene sheets (called “few layer graphene” FLGs) are processed to afford a distribution size that is more suitable for nanomedicine applications. Then, the controlled coating of mesoporous silica (MS) shell having a thickness tailored with the sol-gel parameters (amount of precursor, sol-gel time) around the sliced CNTs and exfoliated FLGs are reported. Furthermore, the drug loading in such mesoporous nanocomposites is investigated in full and the surface modification with an aminopropyltriethoxysilane (APTS) coating leading to a controlled polysiloxane layer provides an ultra-high payload of DOX (up to 3 folds the mass of the composites). Such new CNTs based-nanocomposites are demonstrated to release DOX at low acidic pH, high temperature (T) and remotely when they are excited by NIR light. Such nanoconstructs may find applications as components of innovative biomedical devices (scaffolds implants, etc..) for dual therapy displaying photo-thermal properties combined with drug delivery. In a next work, the loading of hydrophobic drugs at the surface of CNTs followed by the capping of human serum albumin layer was achieved to ensure a biocompatible interface and addressed challenges of tissue engineering. [8] [1] D. Mertz, P. Tan, Y. Wang, T. K. Goh, A. Blencowe, F. Caruso, Adv. Mater. 2011, 23, 5668-5673. [2] D. Mertz, J. Cui, Y. Yan, G. Devlin, C. Chaubaroux, A. Dochter, R. Alles, P. Lavalle, J. C. Voegel, A. Blencowe, P. Auffinger, F. Caruso, ACS Nano 2012, 6, 7584-7594. [3] D. Mertz, H. Wu, J. S. Wong, J. Cui, P. Tan, R. Alles, F. Caruso, Journal of Materials Chemistry 2012, 22, 21434-21442. [4] D. Mertz, C. Affolter-Zbaraszczuk, J. Barthes, J. Cui, F. Caruso, T. F. Baumert, J.-C. Voegel, J. Ogier, F. Meyer, Nanoscale 2014, 6, 11676-11680. [5] X. Wang, X., D. Mertz, C. Blanco-Andujar , A. Bora, M. Ménard, F. Meyer, G. Giraudeau, S. Bégin-Colin, S. RSC Adv. 2016, 6, 93784−93793. [6] C. Wells, O. Bringel, V. Fiegel, S. Harlepp, B. Van der Schueren, S. Begin-Colin, D. Bégin, Mertz D., Engineering of mesoporous silica coated carbon based materials optimized for an ultra-high doxorubicin payload and a drug release activated by pH, T and NIR-light. Adv. Funct. Mater 2018, in revision [7] V. Fiegel, S. Harlepp, S. Bégin-Colin, D. Bégin, D. Mertz, Design of protein-coated carbon nanotubes loaded with hydrophobic drugs through sacrificial templating of mesoporous silica shells, Chem Eur J.,2018, in revision.

Resume : It is quite important to develop reliable and feasible electrochemical sensor for 8-hydroxy-2?-deoxyguanosine (8-OHdG) because its urinary level is related to cancer and the co-existed uric acid (UA) heavily affects its signals. Herein, graphene oxides (GO) was prepared, and then in-situ reduced by Zn powder, and finally a nanocomposite of reduced GO and ZnO nanoparticles (ZnO@rGO) was easily obtained. Compared with the unmodified glassy carbon electrode (GCE) and GO modified GCE (GO/GCE), the ZnO@rGO nanocomposites modified GCE (ZnO@rGO/GCE) significantly increased the oxidation signals of 8-OHdG. Moreover, uricase was employed to eliminate the interferences of UA, and it was found that large amount of UA did not affect the oxidation signals of trace level of 8-OHdG. As a result, a highly sensitive and selective electrochemical method was developed for 8-OHdG determination. The linear range was from 5.0 to 5000.0 nM, and the detection limit was 1.25 nM based on three signal-to-noise ratio. The new monitoring system was used in the clinic urine samples, and exhibited promising practical application.

Resume : A biosensor is defined as a compact analytical device incorporating a biological detection element integrated into a physico-chemical transducer whose purpose is to produce optical or electrical signals proportional to the concentration of an analyte in a sample. Biosensors offer enormous potential for detecting a wide range of analytes in health care, the food industry, environmental monitoring, security and defense. Graphene has received widespread attention as promising carbon-based nanoelectronic devices. Due to their outstanding physical, chemical and electrical properties, namely a surface / solution ratio, improved electron transfer properties and high thermal conductivity, graphene can be effectively used as an electrochemical sensor. The integration of graphene with a functional group provides a good and strong support for the immobilization of enzymes. Determination of glucose levels using biosensors. An enzymatic biosensor with a graphene field effect transistor (FET) detects the glucose molecule by catalyzing glucose to gluconic acid and hydrogen peroxide in the presence of oxygen. This action provides high accuracy and rapid detection rate. This biosensor detected glucose levels by measuring the drain-source current when glucose was oxidized by glucose oxidase which was immobilized the FET of graphene. In this work, a graphene field effect transistor biosensor for glucose detection is modeled analytically. In the proposed model, the glucose concentration is presented as a function of the gate voltage. The simulated data demonstrate that the analytical model can be used with an electrochemical glucose sensor to predict the behavior of the sensing mechanism in biosensors.

Resume : Silk is natural structured material composed of mainly two kinds of amino acids, glycine and alanine up to 80%, resulting in the highly conserved repeat units such as poly-(Gly-Ala) and poly-Ala domains. These repetitive peptide domains promote the polypeptides to construct the β-sheet conformations by numerous inter-/intra-hydrogen bonds, the most stable secondary structure in proteins. And the parallel alignment of these strong β-sheet crystals along the fibre axis results in mechanical robustness and chemical stability of silk. Moreover, the β-sheet crystals are not burned out even after pyrolysis and restructured to form unsaturated or aromatic structures by heating above 350 °C. And by further heating by 2,800 °C, they developed into pseudo-graphitic structures. However, although the exceptional theoretical modulus and strength of graphite up to ~1 TPa and ~120 GPa, respectively, the silk-derived fibres with disordered graphitic structures possess poor mechanical properties even hard to measure. Here, a long-range ordered graphitic structure along the fibre axis can be realized from the inherent microstructure of silk through simple heating with axial stretching. The hexagonal carbon layers, pyroproteins, induced from the β-sheet protein molecules maintain the parallel alignment along the fibre axis and were developed into highly ordered sp2 carbon structure by further heating up to 2,800 °C, resulting in the remarkable tensile strength and Young’s modulus up to ~2.5 GPa and ~450 GPa, respectively. Considering that in the early development stage, the carbon fibres produced from the conventional precursor, polyacrylonitrile, revealed only ~ 1GPa and ~100 GPa of tensile strength and Young’s modulus, respectively, these pyroprotein-based fibres prepared with a facile process show a great potential to surpass the strongest fibres available today. And the lightweight and physicochemical-/thermo-stable characteristics compared with traditional inorganic materials provide them with extensive applications in aero-space, automobile, and civil engineering. In addition, the bio-derived fibres consisting of the large conjugated aromatic domains reveal the high electrical conductivity up to 4.37 × 103 S/cm, expanding their application fields to the high-technology industries such as energy storage/conversion system, e-textile, robotics, bio-electronics, and bio-medicals.

Resume : We report on EPR, 13C and 1H NMR study of detonation nanodiamond particles with surface grafted by paramagnetic gadolinium ions obtained by ion exchange with hydrogen atoms of carboxyl groups through the reaction of aqueous nanodiamond suspension with an aqueous solution of gadolinium nitrate. Our findings give clear evidence that Gd(III) ions are chemically bound to the nanodiamond surface and interact with electron and nuclear spins of the diamond core, which results in acceleration of electron and nuclear spin-lattice relaxation. A model of positioning of Gd(III) ions on the DND surface terminated by oxygen-containing groups is suggested. The distance between the Gd ion and nanodiamond surface is estimated by relaxation measurements as 0.3 nm. Biomedical applications of the studied nanomaterials are discussed. A. M. Panich, A. I. Shames, N. A. Sergeev, V. Yu. Osipov, A. E. Alexenskiy, A. Ya. Vul', Magnetic Resonance Study of Gadolinium-Grafted Nanodiamonds. J. Phys. Chem. C 120, 19804−19811 (2016). DOI: 10.1021/acs.jpcc.6b05403

Resume : We present an insight into the mechanism of the photoluminescence (PL) quenching of carbon nanodots (C-dots) by Cu2+. The results of PL, UV-vis absorption, time-resolved PL, and femtosecond transient absorbance measurements reveal that the quenching occurs by a photoinduced electron transfer (PET) process from the photoexcited C-dots to the empty d orbits of Cu2+. The carboxyl and hydroxyl groups on the C-dots surface can be readily converted to ester and ether, respectively, through a mild reaction with 1, 3-propanesultone to obtain the C-dots with carboxyl and hydroxyl groups being passivated. Moreover, due to the ester can hydrolyze under alkaline condition but the ether cannot, the C-dots with hydroxyl groups being passivated is achieved. Thus, the coordianation effect between Cu2+ and the carboxyl rather than hydroxyl group of C-dots, which leads to an effective PET process, is confirmed. This study leads to a better understanding of the quenching of C-dots and takes an important step toward more rational design of C-dots for various sensing applications.

Resume : Several analytical methods have been published concerning the determination of active pharmaceutical ingredients (APIs) in drug formulations or in environmental samples. The most commonly used are chromatographic techniques but these methods are time consuming, expensive, require complicated preconcentration processes and need sophisticated instruments. On the other hand, electrochemical methods present the advantage of high simplicity, high sensitivity, good stability and low cost. These instruments can also be portable, which is particularly suitable for on-site monitoring of pharmaceuticals in field analysis. In the present work, Carbamazepine, Ibuprofen, Clarithromycin, Naratriptan, Dopamine and Acetaminophen have been determined using different electrochemical techniques at screen printed electrodes (SPE). The spectroelectrochemical behavior of the voltammetric response of some of these APIs allows the selective detection of these compounds despite their similar oxidation potentials on SPEs. The analysis was carried out by simultaneously performing an electrochemical and an optical experiment, the corresponding voltabsorptograms obtained are presented, showing the correlation between the derivative voltabsorptograms at the maximum of absorbances and the electrochemical curve. This work is supported by Innovec`EAU (SOE1/P1/F0173) project from the Interreg Sudoe 2014-2020 program funding by European Regional Development Funds

Resume : Herein, our main aim is to develop a sustainable and greener approach for silver nanoparticle/reduced graphene oxide (AgNPs/RGO) nanocomposite with the aid of gelatin derived carbon dots (C-dots) within a short time span by ultrasonic wave. These C-dots assisted green reduction of AgNPs/RGO nanocomposite requires an ultra-low concentration of C-dots as reducing agent. By using a very little concentration of C-dots from a low-cost source permit large-scale production of AgNPs/RGO nanocomposite without using any rigorous chemicals and tedious extraction or purification methods. Moreover, the inherent reducing property of C-dots enables them for reduction of silver salts to the corresponding silver nanoparticles. Moreover, the reduction is done without using any toxic external reducing agents and any surfactants or stabilizers, thus it can be accepted as green method. Realizing the potential of the gelatin derived C-dots as stabilizing and reducing agents towards the development of nano-composite will certainly lead to eco-friendly pavement for nano-catalysis. The nano-composite exhibits dual performances like engrossing catalytic activity and bactericidal effect towards gram-negative bacteria E. coli. This research can be imposing promising effectiveness and further applicability for fabrication of antibacterial catalytic membranes.

Resume : Luminescent carbon dots (C-dots), a newcomer in the domain of nanolights and nanomaterials have been studied extensively since past few years due to their fascinating properties of sensor design, cell tracking or fluorescence based live cell assays, medical diagnosis, photocatalysis, and also being potential building blocks for nanodevices. In our study, a method of upcycling of waste kitchen chimney oil has been adopted to prepare multifunctional fluorescent C-dots. The C-dots showed good biocompatibility, cyan fluorescence, and their superiority with respect to commercially available synthetic dyes can lead our prepared material as non-toxic, inexpensive fluorescent nanoprobe towards versatile applications. Earlier, synthetic organic dyes were used as bio-labeling materials, but they have severe limitations such as photobleaching effect, high cost, etc. Therefore, our prepared C-dots may be a suitable replacement of the commercial synthetic staining agent for bio-labeling assays. Further, the waste chimney oil derived C-dots have been experimented to sense Fe3+ ion in a wide range of concentration with an ultra-low limit of detection which can be termed as tracer metal chemosensor. Concisely, our work bestows an innovative aspect to the commercialization of C-dots as a potent alternative to synthetic organic dyes for multicolor emitting probes for bio-labeling of MG-63 cells and nano-sensor platform.

Resume : In the past decades, Surface-enhanced Raman scattering (SERS) spectroscopy attracted much attention for the highly sensitive label-free detection of chemical and biological species. A great research effort has been made to fabricate noble metal (Ag or Au) nanostructures incorporating as much as possible Raman hot spots yielding a huge electromagnetic field enhancement thanks to the excitation of localized surface plasmons at resonance conditions. Moreover, taking advantage of the discovery in 2010 of the graphene-enhanced Raman scattering (GERS), graphene based structures are of great interest for Raman-enhanced biosensing. In this work, we report on the synthesis and characterization of a hybrid aerogel based on reduced Graphene Oxide (rGO) decorated with silver nanoparticles (AgNPs) exploitable for the SERS detection of biomolecules at very low concentration. Several synthesis conditions were approached by exploiting a one-pot hydrothermal process, starting from commercial GO and adding either AgNO3 as silver precursor with different additives (such as trisodium citrate) or directly a pre-synthesized Ag colloid. The resulting 3-D porous sponge-like nanoarchitecture provides both a high surface area and a homogeneous spatial distribution of AgNPs arranged in order to maximize the hot spots density. The differently synthesized AgNPs/rGO aerogels were characterized by means of FESEM, XPS and TEM. Promising results were obtained in terms of SERS efficiency (i.e. low Limit of Detection) by using Rhodamine 6G as probe molecule, after immersion for 18 h in aqueous solutions (10-6 M to 10-10 M concentrations range) and drying.

Resume : A simple method has been developed to synthesize carbon dot capped gold nanoflower (CD/AuNF) nanohybrids. In principle, anodic electrochemiluminescent (ECL) carbon dots (CDs) with a lot of reductive functional groups were used to react with oxidative hydrogen tetrachloroaurate trihydrate in the presence of trisodium citrate. The obtained globular CD/AuNF nanohybrids had uniform sizes of 50-60 nm. The CD/AuNF nanohybrids were composed of gold nanoparticle aggregates in the centers and CDs on the surfaces. The easy self-assembly with some bio-molecules of AuNFs and the unique ECL activities of the CDs, made the obtained CD/AuNF nanohybrids promising in biosensing. For instance, a novel ECL aptasensor for thrombin (TB) detection has been developed based on the CD/AuNF nanohybrids. The aptasensor showed good selectivity towards TB. Furthermore, it presented a wide linear response range from 0.5 nM to 40 nM and a low detection limit (S/N = 3) of 0.08 nM.

Resume : In previous reports, an efficient route via a convenient acid-catalyzed dehydration reaction between ortho-quinone structures at the edge of GQDs and 1,2-diamine compounds has been developed to modulate PL emissions of GQDs1. The acid-catalyzed dehydration reaction between ortho-quinones and 1,2-diamines is highly specific and proceeds smoothly under mild condition to produce stable aromatic pyrazine structures. We propose the mechanism for conjugated structures in GQDs to tune the band gap of GQDs. The acid-catalyzed reaction with high specificity also provides a chance to study the electron-donating and electron-withdrawing ability of the edge functional groups on the PL behaviors of GQDs. Herein, we employ this acid-catalyzed dehydration reaction to investigate the edge effect on the properties of GQDs.

Resume : Recently, Surface Enhanced Raman Scattering (SERS) spectroscopy has become popular for the high-sensitivity label-free detection in the field of medical diagnostics. The SERS effect, which yields a huge increase of Raman scattering efficiency, is ascribed to the electromagnetic (EM) and chemical enhancements. The EM enhancement is due to the resonant excitation of localized surface plasmons within noble metal nanoparticles (e.g. Au/Ag NPs). The chemical enhancement can be explained by the charge transfer (CT) from a metal state to a vibrational level within the target molecule. Graphene is well-known to exhibit SERS effects by taking advantage of the CT mechanisms. In such framework, the coupling of a Single Layer Graphene (SLG) to a solid substrate, covered by Ag or Au NPs, would maximize the synergy between the EM and the CT enhancements. In addition, the chemical functionalization of the SLG surface could exploit non-covalent π-π interactions between SLG and polycyclic aromatic molecules (e.g. porphyrins), thus extending the plausible applications of this kind of substrate to SERS biosensing. In this work, we present the coupling of AgNPs, deposited onto an elastomeric support (polydimethylsiloxane, PDMS) suitable for microfluidic integration, with SLG obtained by CVD on Cu substrates. The SERS efficiency of the NPs/SLG substrates was evaluated by using Rhodamine 6G as a probe molecule. The effective surface chemical functionalization of the SLG/AgNPs/PDMS substrates by Protoporphyrin IX and Hemin, before and after the conjugation either with bovine serum albumin (BSA) or with BSA-Fluorescein was demonstrated by Raman analysis. The conjugates were previously characterized by UV-Vis and fluorescence spectroscopy.

Resume : Water-soluble fullerene derivatives have a big potential for biomedical applications owing to their antitumor, antiviral, antibacterial and neuroprotective activities. We have demonstrated recently that chlorofullerene C60Cl6 represents a versatile precursor for the synthesis of a wide range of multifunctional compounds including those soluble in water [Chem. Commun., 2012, 48, 5461; Chem. Commun., 2011, 47, 8298; Chem. Commun., 2012, 48, 7158]. In particular, Friedel-Crafts arylation of C60Cl6 was shown to be one of the most efficient methods for preparation of water-soluble С60Ar5Cl derivatives bearing five appended fragments of arylalkylcarboxylic acids. Here we report the synthesis, characterization and investigation of antiviral properties of >30 novel highly water-soluble fullerene derivatives С60Ar5X (X=H, Cl, Me, Et, iPr, nBu, iDec). Replacement of Cl in С60Ar5X with H was achieved using Ph3P/H2O method reported by Taylor (J. Chem. Soc., Perkin Tans., 1997, 2, 457). Alkylated compounds were obtained from С60Ar5Cl using a novel cross-coupling reaction. A group of C70 derivatives has been synthesized from C70Cl8-10 using a similar arylation approach. The obtained water-soluble derivatives of C60 and C70 comprised 5 to 16 carboxylic groups in their molecular frameworks. Multiple compounds revealed low toxicity in combination with a potent activity against influenza, HIV, CMV and HSV, which makes them promising lead structures for development of novel antiviral drugs.

Resume : The bisporphyrin-based flexible nanotweezers with various metal were synthesized and applied to the extraction of single-walled carbon nanotubes. Homo- and hetero-metallic bisporphyrins including Co2+ were found to afford higher SWNT-extraction ability, while no or a little amount of SWNTs were extracted by bisporphyrins with other metals.

Resume : In contrast to soluble host–guest system, the heterogeneous nature and the insolubility of the SWNTs make impossible the determination of the molar concentration of SWNTs in solution, which limits the understanding of the supramolecular association of SWNTs. However, a new and simple procedure for the quantitative determination of association constants between soluble molecules and insoluble carbon nanotube CNT samples has recently been reported. In this paper, we applied this method to determine the association constants of SWNTs with pyrene, pyrene-based nanotweezers, and pyrene-nanocalipers, with SWNTs. The procedure is as follows: SWNTs (65-CoMoCAT) were suspended in a solution of known concentration of the host, stirred for two hours and filtered. After thermogravimetric analysis of the filter solid, association constant was calculated by plotting the degree of functionalization against the concentration of the free host. The association constants (Ka) determined in DMF. The nanotweezers 2 and nanocalipers 3 exhibit higher association constants ((4 ± 2) x 10^3 and (5 ± 2) x 10^4) than pyrene 1 (12.6 ± 0.6) by two and three orders of magnitude, respectively. This trend is proportional qualitatively to the number of interactions between the host molecules with SWNT surface to stabilize the complexes. We will also determine the association constants of porphyrin and porphyrin-based nanotweezers and nanocalipers, and will compare with those of the pyrene analogues.

Resume : Solubilization of single-walled carbon nanotubes (SWNTs) is one of the key technologies for promoting the practical application of SWNTs in many fields. Herein, we report an efficient individualizing and dispersing method for SWNTs through noncovalent functionalization. The dispersant, 2,3,6,7,10,11-hexahydroxytriphenylene, exhibited very high ability to disperse SWNTs. Typically, about 68wt% of the initial SWNTs were well dispersed in water at the hexahydroxytriphenylene concentration of 25 mg/L, giving a dispersing efficiency (the amount of SWNTs dispersed by one mmol dispersant) of 2.2x10^2 mg/mmol, as revealed by absorption spectrum and scanning transmission electron microscopy (STEM). This dispersing efficiency is hundred times larger than that of widely used small molecular dispersants including SDBS and SDS, and much larger or comparable to that of polymeric dispersants. Raman spectra indicated that the dispersion process did not introduce any obvious defects and separate any specific (n, m)-SWNTs. The very high efficiency of 2,3,6,7,10,11-hexahydroxytriphenylene is supported by its large association constant (Ka) with SWNTs, (7±1) x10^4 M^-1, which is four order of magnitude larger than that of other dispersants.

Resume : We have been developing host-guest chemistry for separation of carbon nanotubes (CNTs) according to diameter, metallicity, and even handedness. The host molecules named “nanotweezers” consisting of a rigid core and two receptors were designed and applied to CNT separation. To apply this methodology for separation of wider range of CNTs in better selectivity, “nanocalipers” have been designed, which include a core, two corners, and two receptors. In this review, we focus on “nanocalipers”, a new host molecule next to the nanotweezers, from their moelcular design and synthesis to CNT separaion.

Resume : Up to now, the colloidal gold labeling immunochromatographic test strip is a mature and applicable technology. However, different from the conventional gold nanoparticle, quantum dot (QD) possesses larger specific surface area and better biocompatibility. So, as a novel nanomaterial, QD is capable of assembling more biomolecule which could enhance the sensitivity and accuracy of strips by rationality. Besides, strand displacement amplification was drawn into our test strips in this paper, this assumption made HIV-DNA recycling many times and converting it to plentiful QD-dsDNA (double-stranded deoxyribonucleic acid), where after these nano-structures would be captured by test zone. Meanwhile, the suggested scheme eliminated the hook effect owing to the target drop out of the incorporation on test zone, and any nucleotide sequence or substance which has aptamers can work as the target, such as carcinoembryonic antigen or mycotoxin. This assay realized the detection limit of as low as 0.76 pM (S/N=3) and the detection range of 1 pM to 10 nM. In the end, we made use of this fluorescent lateral flow assay strips with great reproducibility for detecting HIV-DNA in human serum, that attested this method could be applied to practical application prospectively.

Resume : Metal nanoclusters have attracted wide attention due to their distinctly different optical and chemical properties. Among them, DNA-templated silver nanoclusters (AgNCs) can be directly used as a signal probe for the construction of electrochemical biosensor. In this work, a novel electrochemical biosensor was developed for DNA methyltransferase activity detection based on hybridization chain reaction (HCR) formed DNA as the template of AgNCs. As to the construction of biosesnor, graphene/gold nanoparticles complex was electrochemically deposited on the surface of glassy carbon electrode for the immobilization of capture DNA. Subsequently, assistant DNA hybridized with the capture DNA to form double-stranded DNA contianed the identification site of the DNA methyltransferase. Without the exsistance of DNA methyltransferase, the identification site could not be methylated, which hindered the cleavage of methylation-sensitive restriction enzyme (DpnI). The followed HCR process generated large amount of C-rich DNA on electrode to act as the template of AgNCs for electrochemical signal output. The presence of target could methylate the identification site, which triggered the cleavage activity of DpnI and supressed the subsequent HCR process, thus less AgNCs were formed, and the signal of AgNCs decreased. The proposed biosensor realized quantitative determination of DNA methyltransferase activity with a detection limit of 0.007 U/mL, which held great promise as an effective method for methyltransferase activity detection.

Resume : Recently experimental and theoretical works have reported that graphene quantum dots (GQDs) a unique form of zero dimensional nanostructure, and their exceptional properties including low toxicity, photo-stability, biocompatibility and the tunable optoelectronic properties such as photoluminescence (PL) make them promising in biosensing applications. Surface-enhanced Raman scattering(SERS) is an ultra-sensitive analytical technique for trace molecules detection. While the potential of SPR metals (e.g. Au and Ag) and graphene for SERS has been demonstrated, but the work of GQDs applied as SERS substrates is still lacking. First we compare the SERS property of three kinds of GQDs with different emission wavelength, systematic Raman results using R6G as the Raman probe molecules show that SERS enhancement of GQDs is highly influenced by the molecular adsorption ability. Furthermore, modified GQD with metal nanostructure will lead to important advance for SERS-based detection. The conventional approaches to synthesize GQD-metal nanohybrids including UV irradiation method and wet-chemistry reduction are time-consuming and requiring toxic chemicals. Here we demonstrate a facile synthesis of GQD-AgNP nanohybrids using the atmospheric-pressure microplasma-assisted electrochemistry. By carefully adjusting the plasma parameters (i.e. time, current, and voltage), the microplasma-assisted electro-chemical reaction showed the possibility to grow Ag nanostructures onto the GQD surfaces within minutes. Detailed UV/Vis spectroscopy and fluorescence spectroscopy were used for optical property study of GQDs and GQD-AgNP nanohybrids. Transmission electron microscopy (TEM) characterizations show that the size distribution and the morphologies of as-produced nanohybrids could be controlled to form the heterodimeric nanostructures. Systematic Raman study indicated the as-produced GQD-AgNP nanohybrids can further enhance SERS performance and there was an intimate relationship between the fluorescence resonance energy transfer(FRET) of the as-produced nanohybrids and their SERS properties in our study.

Resume : Nanodiamonds (NDs) are promising material for medical field due to its huge specific surface area, ease of surface modification and biocompatibility. Previously, our group demonstrated that polyglycerol-functionalized fluorescent NDs having a 50 nm diameter (FND50) was taken up by cancer cells and showed strong fluorescence in the lysosomes [1]. In this research, we further extend the usage of NDs as cancer therapy agents utilizing the nature of passive targeting to cancer cell. First, we tried to apply FNDs to in vivo tumor imaging. We have adopted FNDs with a diameter of 100 nm to maximize targeting ability and fluorescence of each particle. FNDs are functionalized by polyglycerol (PG) to make the FNDs have more dispersibility in the medium. The resulting material, FND100-PG, shows good stability in both water and physiological environment as the medium. We succeeded in induction of FND100-PG to a mouse by intravenous injection. After 4 hours, the mouse did not die and strong fluorescence was observed from the liver and the tumor by in vivo and ex vivo photoimaging, respectively. A point worthy of special mention, strong fluorescence from the tumor was observed in the young tumor because uptake ability seems to attenuate as the tumor grows. NDs could be delivered to early- stage cancer considering this result. Next, we are going to apply NDs as DDS carrier. By conjugating anti-cancer drug such as cisplatin, NDs could be applied to cancer therapy. [1] L. Zhao. et. al. Adv. Funct. Mater., 24, 5348 (2014).

Resume : Carbon nanotubes (CNTs) are widely used for industrial and bio-related applications due to its exceptional electrical, mechanical and thermal properties. As the use of CNTs in industrial processes has increased, the safety issue of CNTs becomes more and more emphasized in these days. It is prerequisite to validate the safety of those products on the environment and human health for the prospective growth of nanoindustry. To understand the relationship between physicochemical properties and nanotoxicity, it is required to develop reliable disperse techniques adequate for the analysis of toxicity test. In the CNTs toxicological characterization, dispersing process in aqueous solution is essentially needed to get reliable results prior to toxicity test initiation. In spite of many in vivo and in vitro studies, the toxicity of CNTs is still equivocal in the absence of proper standard dispersion protocol. The main approaches for dispersing CNTs are oxidization or functionalization treatments which can induce structural defects but also change behavior. In this study, we evaluated a reliable multi-wall carbon nanotubes (MWCNTs) dispersion protocol that can be used for the toxicity testing. The two types of MWCNTs were purchased from Arkema(GRAPHISTRENGTH C100, France) and Nanocyl(7000s, Belgium). We prepared several dispersants for MWCNTs which are already known as non-toxic and biocompatible dispersants, like PBS (100 mM, pH 7), BSA (bovine albumin serum), TWEEN 80 and DPPC(dipalmitoylphosphatidylcholine). NANOGENOTOX dispersion protocol was adopted for this study so that dispersions have equivalent size distribution between batches. In addition, appropriate ratio between MWCNTs and dispersant’s concentration was discussed. The morphologies of MWCNTs are observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The stability of dispersions for 4 weeks, the hydrophobicity index and reproducibility of each dispersion were quantitatively evaluated using UV-vis spectrometry and dynamic light scattering (DLS). The measurement methods used and the most capable dispersant for toxicological testing will be demonstrated in this presentation.

Resume : The allotropic transformations of carbon provide an immense technological interest for tailoring the desired molecular structures in the scalable nanoelectronic devices. Herein, we explore the effects of morphology and geometric alignment of the nanotubes for the re-engineering of carbon bonds in the heterogeneous carbon nanotube (CNT) networks. By applying alternating voltage pulses and electrical forces, the single-walled CNTs in networks were predominantly transformed into other predetermined sp2 carbon structures (multi-walled CNTs and multi-layered graphitic nanoribbons), showing a larger intensity in a coalescenceinduced mode of Raman spectra with the increasing channel width. Moreover, the transformed networks have a newly discovered sp2–sp3 hybrid nanostructures in accordance with the alignment. The sp3 carbon structures at the small channel are controlled, such that they contain up to about 29.4% networks. This study provides a controllable method for specific types of interallotropic transformations/ hybridizations, which opens up the further possibility for the engineering of nanocarbon allotropes in the robust large-scale network-based devices.

Resume : Carbon materials have great potential for advanced nanotechnology. They exist in various allotropes in several dimensions, such as 0D of C60 family and graphene quantum dots, 1D of carbon nanotube (CNT), graphene nanoribbon (GNR) and carbon fiber (CF), and 2D of graphene related materials. Each of these allotropes shows unique and interesting properties making them representative nano-materials. Recently, hybrid system of those different carbon allotropes has great attentions to achieve an improved and synergetic properties. Making 3D hybrid structure gives many enhanced properties, such as high integrity, interconnectivity, porosity, conductivity and mechanical strength. New strategy to connect different carbon allotropes with covalent bonding allows us to fabricate more advanced structure which was not possible previously and to understand novel properties of materials. After first research about seamlessly connected graphene and carbon nanotube hybrid structure (G/CNT) has been reported, it has attracted great attentions due to its high surface area, excellent electrical and mechanical properties. In this presentation, several researches derived from G/CNT structure will be introduced, such as patterning, mechanical strength at the junction and energy storage application, and its powerful possibility will be discussed.

Resume : Nickel oxide nanoparticles were decorated on reduced graphene oxide via simples and easy reduction of graphene oxide and nickel salt in a single step reaction. The nanocomposite material has been characterized using various analytical techniques, including scanning electron microscopy (SEM), energy dispersive X ray (EDX) spectroscopy, UV-visible spectrophotometry and Fourier-transform infrared (FTIR) spectroscopy. The nanocomposite was found to be very efficient for anionic and cationic dye adsorption with complete removal within less than 4 min. The performance of the (rGO/Ni NPs) nanocomposite is quite high as compared to other graphene-based adsorbents. After completion of the reaction, the (rGO/Ni NPs) nanocomposite could readily be recovered by centrifuge and could be reused for ten runs without any significant loss of its activity. More importantly, the photocatalyst did not show any leaching during the reaction as confirmed by ICP-AES analysis of the recovered catalyst.

Resume : Recently graphene quantum dots (GQDs) have been shown with superior tunable optoelectronic properties including photoluminescence (PL) properties. In addition, GQDs demonstrate exceptional solubility, cytotoxicity and biocompatibility, making them useful in biomedical applications including biosensing, drug delivery, and cancer therapy. However, the conventional approaches to prepare GQDs are encountered some difficulties , which is inclusive with expensive raw materials, complicated operation, time consuming inefficiency, and high temperature required. Nevertheless, challenges still remain with respect to fabrication of tunable emission wavelength that could be construct multifunctional sensing systems. Hence, we present a green and facile microplasma-assisted synthesis of GQDs from biomass (i.e. starch). Microplasmas are defined as gaseous discharges formed in electrode geometries where at least one dimension is less than 1mm, which can be operated stably with an aqueous solution at atmospheric pressure. Energetic species formed in the microplasma are capable to initiating electrochemical reactions and nucleating particles in solution without chemical reducing agents, and played a main role in the preparation of nanostrutures. We used starch, one of the most common biomass resource, as the carbon precursors. Significantly, detailed characterizations including UV-vis absorption, PL, and Raman spectrscopies and microscopic analysis including AFM and TEM suggest that the PL emissions of GQDs could be tuned by simply adjusting the currents of microplasmas and the concentrations of starting starch aqueous solutions. It is also noted that the as-prepared GQD dispersions in DI water were highly stable without obvious precipitation up to 1 month.

Resume : Recently, the colloidal graphene quantum dots (GQDs) have attracted a lot attentions due to their superior properties such as good bio-compatibility, high photostability and tunable optical properties, making them promising for emerging applications. Howevr, current synthesis methods usually involve high temperature, costly and complex processes. Consequently it is important to develop a method to synthesis of stable colloidal GQDs for potential applications and understanding the new quantum-confined process in carbon materials. Here we report a facile synthesis of stable colloidal graphene quantum dots using atmospheric-pressure microplasmas. In this work, aromatic hydrocarbons such as Naphthalene and Methylnaphthalene were used as the carbon precursors. Atmospheric-pressure, argon (Ar) microplasmas were operated with the carbon-containng presursor aqueous solutions. In this condition, energetic species including radicals, ions and electrons formed in the microplasma were capable of initiating electrochemical or non-electrochemical reactions witnin the electrolyte (i.e. presursor aqueous solutions). Detailed materials characterizations including UV-Vis, Raman, and photoluminescence spectroscopies, and microscopies including TEM and AFM suggest that the developed microplasma-assisted electrochemistry method possesses the ability to fabricate colloidal GQDs. Moreover, we noted that the yield of the as-produced colloidal GQDs could be incrased using different chemical pre-treatments before or during the plasma process, suggesting that the reaction intermidates generated by the pre-treatments played a crucial role in the GQD synthesis. Our study provides the insight to understand the fundamental factors to enhance the GQDs yield using plasma-enhanced reactions.

Resume : Primary amino group on nanodiamond surface will serve as a scaffold to bind or adsorb proteins, DNAs, saccharides or small drug molecules etc. for various biomedical applications. A lot of studies to introduce primary amino group had been reported. In almost all cases, the processes were relevant to introduction of small molecules already possessing amino groups. Hence the amino group was bound on the surface carbon directly. Here we will report about our attempts for the production of primary amino group directly bound to the surface carbon atom of detonation nanodiamonds. Reduction by borane-tetrahydrofuran (THF) complex is often exploited to produce hydroxyl group from carboxylic acid. We deduced that hydroboration reaction also occurred by the borane-THF treatment on nanodiamond since residual boron was determined in the treated sample. The sample was subsequently treated with hydroxylamine-O-sulfonic acid to convert borane moiety on the surface into amino groups. The detail of experiments and the results of quantitative analysis of amino group will be presented and discussed.

Resume : An advanced yet recent development of the sputtering technique is high power impulse magnetron sputtering (HiPIMS), in which short, energetic pulses are applied to the target. An ultra-dense plasma is thereby formed in front of the cathode that provides a variable degree of ionization of sputtered material, and consequently enables to control the energy and the direction of the depositing flux. This gives a possibility to alter composition and microstructure in a controlled manner, enabling the optimization of TiC/amorphous carbon (TiC/a:C) for biomedical applications. The aim of this work is to link physical phenomena in transient HiPIMS discharges to elemental composition, microstructure, morphology and biocompatibility of graded TiC/a:C coatings. Auger electron spectroscopy (AES) analysis together with morphology examination revealed an increased number of sp2-rich clusters in a-C films grown by chopped HiPIMS (c-HiPIMS). C-HiPIMS a-C films are more hydrophobic with a contact angle difference of about 9 % in comparison to the direct current magnetron sputtering (dcMS) films at an average power of 250W. The metabolic activity of human fibroblast cells cultivated on the samples grown by c-HiPIMS is about 20 % higher than that of the samples deposited by dcMS. The increased metabolic activity is due to a confluent cell layer on these surfaces. The investigation of the cell morphology revealed no negative influence on biocompatibility for both deposition methods.

Resume : Boron neutron capture therapy (BNCT) is a promising binary therapy for the treatment of cancer, because malignant cells can be selectively targeted and destroyed in the presence of healthy normal cells. A large number of functionalized boron clusters have been designed as boron delivery vehicles. The [B12H12]2- and [M(C2B9H11)2]- (M=Co or Fe) possess exceptional chemical and hydrolytic stabilities, uncommon physico-chemical properties in water and low toxicity, making them and their derivatives ideal candidates for BNCT. An important point is the assessment of the amount of 10B that has reached the target sites, which must be monitored during the in vivo biodistribution. BODIPY-type molecules have found application in imaging, biological labeling and fluorescent probes due to their remarkable high extinction coefficients, low molecular weights, high photochemical stabilities and membrane cell permeability properties. Therefore, boron clusters-substituted BODIPY dyes could show enhanced permeability and are promising as boron delivery drugs for BNCT. Herein, the design, synthesis, characterization and fluorescence study of a new family of BODIPY derivatives will be presented. Linking the BODIPY to [B12H12]2- and [M(C2B9H11)2]- affords fluorescently labelled molecules that allow to know their biodistribution and cellular uptake. The internalization of the dyes inside cells can be monitored through flow cytometry and confocal microscopy analyses.

Resume : Carbon-based materials are considered ideal electrode materials due to their wide anodic potential range, low residual current, chemical inertness, ease of processing, availability and low cost. These electrodes possess attractive electrochemical activity with high mechanical stability, in addition to the availability of various forms of carbon in nature. For sensors of comparable size, the surface to volume ratio controls the number of active sites that are in contact with the analytes and thus the sensitivity. The efficiency of the electronic interactions between the electrochemical surface and the analyte on the other hand directly affects the measurement. Large surface area coupled with high mobility and conductivity are potential advantages of graphene for electrochemical sensors. Reduced grapheme oxide (rGO) and its derivatives have in particular found large interest for electrochemical sensing applications. We demonstrate the benefit of electrophoretic deposition (EPD) of reduced grapheme oxide/polyethylenimine (rGO/ PEI) for the selective modification of a gold (Au) microelectrode in a microsystem comprising a Pt counter and a Ag/AgCl reference electrode. The functionalized microsystem was successfully applied for the sensing of dopamine with a detection limit of 50 nM. Additionally, the microsystem exhibited good performance for the detection of dopamine levels in meat sample.

Resume : The results obtained through the optimization of molecules gave us the different distances and angles according to the methods and bases applied with a C2v symmetry. We were able to determine the total energies, the energy gap ΔE (HOMO-LUMO) of the four conformers trans-transoid; trans-cisoid; cis-transoid; cis-cisoid. (the semi empirical AM1+PM6 at 6-31G and 3-21G** levels) and finally a comprehensive analysis on the topological charges. The analysis of the results show that for the eight molecules, the trans-transoid conformer is energetically very stable compared to the cis-cisoid one, this stability is confirmed by the obtained values for the total energy. The increase in the stability energy leads to a less important Homo-Lumo energy gap. The analysis of the optimized geometrical parameters of the ten molecules using the AM1 and PM6 methods, are in agreement with the experimental structures characterized by X-ray diffraction. Finally, we were able to determine the reaction profiles of the Cis-Trans isomerization reactions of the decapenta-ene in the gas phase, and to calculate the activation energy (Ea), as well as the diagrams of energies E (eV) based on the coordinates of the isomerization reaction of its molecules, and molar absorption according to energy calculated by the method HF at 6-31G and 3-21G** levels. Thus we have to determine the Spectrum IR of all the molecules by (AM1) and PM6. Keywords: substituted decapenta-ene , semi empirical, HF (AM1+PM6),

Resume : Vascular endothelial growth factor (VEGF) is an overexpressed signal protein observed in cancerous cells and is responsible for the uncontrolled angiogenesis that promotes the growth and metastasis of virtually all forms of cancer. As a result, the overexpression of VEGF can be an important biomarker for indicating the presence of cancerous tissues. Fluorescent nanodiamonds have been functionalized via click chemistry mediated attachment with VEGF-A protein. Subsequent in vitro administration and analysis demonstrate effective conjugation and targeting of the VEGF modified diamond to VEGF cellular receptors (VEGF-R). Thus, an effective demonstration of click chemistry mediated conjugation and targeted in vitro administration of fluorescent nanodiamonds is shown, and the results show continued promise for the use of fluorescent nanodiamonds as a targeted fluorescent probe.

Resume : The utility of fluorescent nanodiamonds (FNDs) for in vivo bio-imaging was investigated. Fluorescence of ND as a function of size and concentration was measured via a whole-body imaging system to help determine optimal sizes for in vivo detection. This baseline analysis determines a threshold as to expected imaging signal from whole-body imaging systems. ND was then administered via tail vain injection to nude BALB/c mice induced with a 4T1 mammary carcinoma to determine particle biodistribution via both whole-body imaging and supplemental ex vivo analysis. Due to ND stability against acidic conditions, tissues were digested and analyzed to provide quasi-quantitative assessment of tissue loading. In post-analysis microscopy of tissue, the unique spectral shape of nitrogen-vacancy induced fluorescence provided unambiguous determination of ND translocation to specific organs. These results are then placed in the context of FND for whole-body imaging and related applications.

Resume : Recently, the development of methods for the rapid and sensitive detection of protein biomarkers has shown great importance for the early diagnosis of diseases. This work combines the electrochemical signal transduction of a ferrocene (Fc)-stabilized graphene nanoprobe with a magnetic bead (MB)-based sandwich immunoassay to develop a new biosensing method for the convenient and accurate detection of the protein biomarker of PSA. The nanoprobe was prepared through the π-π stacking assembly of ferrocenecarboxylic acid on the surface of graphene followed by the covalently linking of capture antibody on the resultant nanocomposite. This surface functionalization not only enables the simple loading of high-content electroactive indicator of Fc on the graphene nanocarrier and also ensures the good dispersibility of the graphene nanocomposite. Based on the sandwich immunoreaction at the constructed MB-assay platform, the nanoprobes were quantitatively captured to form a magnetic immunocomplex. After treating with a weakly acidic solution, the graphene-Fc nanocomposite were dissociated from the immunocomplex and thus produced corresponding electrochemical signal at an electrode. This led to the successful construction of the biosensing method. Due to the great electrochemical signal enhancement of graphene and the rapid and convenient operation of the MB-based sandwich immunoassay, excellent analytical performance was achieved to this method.

Resume : Detonation is a technique for manufacturing 5 nm diameter nanodiamonds, which are known as detonation nanodiamonds. Although these nanodiamonds are believed to have numerous NV centers, only a small fraction of them are optically active. As a result, the vast majority of detonation nanodiamond particles remain non-fluorescent for reasons that are not completely clear. On the other hand, bright and stable optically active NV fluorescent centers can be produced by irradiating microcrystalline diamonds that are synthesized by high pressure, high temperature (HPHT) processes. Reduction of size of these microcrystalline diamonds by milling yields brightly fluorescent NV nanodiamonds with the sizes down to 40 nm. However, milling of microcrystalline diamonds is a long and expensive process. Here, we investigate the possibility of producing smaller NV fluorescent nanodiamonds by mixing commercially available NV nanodiamonds with diameters ranging from 40 to 100 nm with explosives and detonating in the conditions typical for detonation nanodiamond synthesis. We purify and isolate the NV fluorescent nanodiamond nanoparticles, then determine their size and fluorescence after detonation. The behavior of NV fluorescent HPHT nanodiamonds in detonation environments and the potential to use detonation as a cheaper and faster way to reduce the size of NV fluorescent HPHT nanodiamonds below 40 nm will be discussed.

Resume : The lifetime of the rich variety of modern products is limited by the degradation of the engineering (structural and functional) materials from which they are constructed leading to the product’s complete failure. Many future materials cannot be frequently replaced due to efficiency or cost considerations and require a long operational time. Spacecraft materials for example should properly operate for the entire mission duration of years. Replacement of faulty spacecraft materials is either prohibited or extremely expensive (a famous high cost repair procedure is that of the Hubble Space Telescope). Self-healing is the way by which Nature repairs damage in bio and botanic entities and prolongs their life. The formation of local damage in such self-healing natural materials initiates mending processes resulting in the healing of the defected region. Note that Nature commonly compromises the materials’ strength to achieve self-healing properties which are very often more important than the absolute strength. The ability of Nature to self-repair local damage, sometimes to complete restoration, inspired material scientists/engineers to design and process “self-healing” materials in which the damage (e.g. breakage of bonds or crack formation) initiates a healing response. The self-healing process should take place spontaneously and without human intervention. A variety of (very often complex and expensive) concepts have been applied to achieve self-healing materials. Healing also involves local repair of a damaged region, but in contrast to self-healing requires some intervention (i.e. application of a compressive pressure). This manuscript reports a simple, versatile and cost-effective methodology for initiating healing in bulk polymers (serving as structural materials) and self-healing and anti-corrosion properties in polymer coatings (serving as protective coatings): introduction of carbon dots (CDs), 5 nm sized carbon nano-crystallites, into the polymer matrix forming a composite. The CDs are blended into poly-methacrylate (PMMA), polyurethane (PU) and other common polymers before or after polymerization. The healing/self-healing process is initiated by interfacial bonding between the locally exposed CDs and the polymer matrix and can be optimized by modifying the functional chemical groups which terminate the CDs. The healing properties of the polymer-CDs composites are evaluated by two ways: (1) comparing the tensile strength of pristine (bulk and coatings) composites to those of fractured composites that were healed, (2) by following the self-healing of scratches intentionally introduced to polymer-CDs composite coatings. Note that such introduced scratches completely disappear within 48 hours at room temperature without any external intervention. The composite coatings not only possess self-healing properties, but also have superior anti-corrosion properties compared to those of the pure polymer coatings. The present work provides a novel, very simple, cheap and versatile way to induce self-healing and anti-corrosion properties in a large number of useful polymers opening the door for the realization of a host of practical applications.

Resume : As it was shown earlier [1,2], fluorescence properties of detonation nanodiamonds (DND) significantly depend on intermolecular interactions in the suspensions. The study of influence of intermolecular bonds of the environment on the DND fluorescence will help to identify still unexplained origin of DND fluorescence. In this study, aqueous suspension of DND with different surface functionalization - hydrophilic carboxylated DND-COOH, hydrophobic hydrogenated DND-H - and surfactant octanoate sodium (NaC8) were studied using fluorescence and Raman spectroscopy. It was found that critical concentration of micelle formation of NaC8, network of hydrogen bonds in suspension, DND fluorescence are strongly affected by interactions of DND surface groups with surfactant and water molecules. The obtained results confirm the hypothesis about the surface origin of DND fluorescence. The study was supported by Russian Science Foundation (grant #17-12-01481). References 1. T. A. Dolenko et al. J. Phys. Chem. C. 116 (2012), 24314. 2. T. A. Dolenko et al. Phys. Status Solidi A. 212 (2015), 2512.

Resume : Irradiation of synthetic and natural diamonds with high energy particles produces optically active crystallographic defects that are useful for a variety of applications. Within the N-related family of optical defects, the nitrogen-vacancy defect (NV-) has been received great consideration due to numerous applications in both emerging and mature technologies: background-free and long-term cell imaging in the red/near infrared spectral region, tracing of cell progeny, flow cytometry, super-resolution imaging, correlative and multimodal microscopy, labeling of low-abundance cellular components. Significant part of defects in diamonds, including NV- centers and their precursors carry unpaired spins and, thus, are paramagnetic. It turns Electron Paramagnetic Resonance (EPR) spectroscopy into powerful practical tool for successive development and optimization of micro- and nano-diamonds having useful properties specifically pre-engineered for biomedical applications. Conventional CW X-band EPR spectra recorded within so called “half-field” (around g = 4.00) region allow both classification and reliable quantification of paramagnetic defects having electronic spin S >= 1 for bulk single- and poly-crystalline diamond samples. Thus, EPR studies of initial nitrogen content, fluence, annealing and nanonization (size) dependences allow optimization of the technological processes for the manufacturing of bright micro- and nano-sized fluorescent diamonds.

Resume : Nano-crystalline diamond is a new carbon phase with numerous intriguing physical and chemical properties. Small doped nanodiamonds find increased use as novel quantum light source in quantum optics and sensors in biomedical applications. We have recently developed a new approach to the synthesis of nanodiamond based on high-pressure high-temperature treatment of its molecular analogue, adamantane1. The variation of the synthesis parameters and the addition of adamantane derivatives containing various elements (N, Si, etc.) to the precursor make it possible to control the size of the nanocrystals synthesized and the content of the luminescing impurity in them. A series of samples was produced from adamantane and adamantanecarbonitrile mixture under variation of adamantanecarbonitrile content. The ability to control content of nitrogen and NV centers in the nanodiamond by changing the mass ratio between adamantane and adamantanecarbonitrile was demonstrated. Uniform mixing of two organic compounds at the molecular level made it possible to obtain an even distribution of NV centers in the volume of diamond crystallites. This work was supported by Russian Science Foundation, grant No 14-12-01329. 1. E.A. Ekimov, O.S. Kudryavtsev, N.E. Mordvinova, O.I. Lebedev, I.I. Vlasov. ChemNanoMat (2018) DOI 10.1002/cnma.201700349.

Resume : Carbon dots (CDs) are emerging new nanocarbons which are considered for many applications in bioimaging or energy harvesting among others. Tuning the CDs surface chemistry enables the modulation of their fluorescence properties but its impact on the electronic and chemical structure of CDs remains unknown. Here the electronic and chemical structures of non-functionalized, carboxylated and aminated CDs will be compared, combining experimental and theoretical approaches. The electronic structure of CDs was characterized by soft X-ray absorption (XA) and X-ray emission (XE) spectroscopies, probing unoccupied and occupied electronic states, respectively, at the carbon and oxygen K edges using the synchrotron BESSY II. The interpretation of XA spectra will be discussed based on theoretical calculations. The chemical structure of the CDs and its modification induced by water adsorption was characterized by ATR-FTIR. We previously demonstrated that monitoring the OH vibrations of water molecules during exposure to humid air was a powerful method to probe H-bonding environment around nanodiamonds.1 For CDs, extremely different surface-dependent water adsorption profiles were observed. Our results suggest that the surface chemistry of the CDs significantly modifies their electronic and vibrational signatures, which has dramatic impact on how they interact with water molecules. This might influence their luminescent properties and their interaction with biological media. Surface termination of CDs should therefore be taken into account for future biomedical applications. 1. Petit et al. Unusual Water Hydrogen Bond Network around Hydrogenated Nanodiamonds. J. Phys. Chem. C 121, (2017).

Resume : The unique properties of carbon nanoparticles (CNP) make them promising for applications in biomedicine. However, in such applications it is necessary to understand how these properties change under the influence of the network of hydrogen bonds developed in such environment as water and biological materials. The interactions of various nanodiamonds (ND) and carbon dots with the surrounding molecules in normal and heavy water, protonic solvents, solutions of salts, surfactants, DNA and proteins were studied using Raman, IR and luminescence spectroscopy. To clarify the role of the surface chemistry, ND with polyfunctional surface and with surface groups COOH, OH, F, H were investigated. The significant influence of CNP on the strength of hydrogen bonds of solvent, on the one hand, and the influence of hydrogen bonds of the environment on the CNP properties, on the other hand, were discovered for the first time. A correlation between increasing CNP luminescence and weakening of hydrogen bonds was established. The dependence between the efficiency of interactions of DNA, proteins and salt ions with ND surface groups and the changes of ND luminescence was found. The obtained results should be taken into account when using CNP in biomedicine. This study has been performed at the expense of the grant of Russian Science Foundation (project No 17-12-01481).

Resume : pH changes accompanying electrochemical reactions at carbon electrodes are common, for example associated with proton and oxygen reduction, or water oxidation. Many redox processes are also coupled to proton transfer, including those of significance in biosensing, for example the oxidation of hydroquinone and related molecules such as dopamine. The pH at the surface of the electrode may therefore differ significantly from that at the bulk, even when buffered electrolytes are used. However it very difficult to measure the pH directly at the interface while the reaction of interest is proceeding. Confocal fluorescence microscopy has been demonstrated as a useful tool for the study of this problem, but the range of pH under investigation is limited by the pKa of the fluorescent probe used. In this talk the use of in situ infra red (IR) spectroscopy for the measurement of electrode interfacial pH will be described. Use of phosphate buffer electrolytes allows the IR absorption bands for the different phosphate species to be measured. As the relative proportions of the phosphate ions in solution is a function of pH, changes in IR absorption allow us to measure the gain and loss of these species and hence the pH change of the solution with high resolution. Moreover, the experimental design allows us to measure changes in pH at a carbon nanotube modified electrode as a function of applied potential.

Resume : Aberration-corrected high-resolution transmission electron microscopy (AC-HRTEM) has enabled atomically resolved imaging of molecules adsorbed on two-dimensional (2D) materials like single-layer graphene (SLG), graphene oxide (GO) and few-layer-graphene (FLG). However, high-precision HRTEM structural characterization of molecules on surfaces is limited by the challenges confronted in deposition techniques of complex molecules on substrates, the ability to achieve high chemical-purity molecular films and the selective immobilization of atoms, molecules and complex aggregates. Widely used solution-based deposition methods lack selectivity and specificity. On the other hand, vacuum-based deposition is an excellent alternative and possesses high chemical purity and control, but in many cases is hindered by the lack of volatility of the molecule of interest. In this work we show imaging of single Phosphotungstic Acid (PTA) molecules by AC-HRTEM at 80 kV accelerating voltage by depositing them on free-standing graphene by electro-spray ion-beam deposition (ES-IBD) [1] at varying landing energies and coverage in vacuum. This approach combines the advantages of free-standing graphene as substrate with the highly pure, chemically selective deposition of mass-filtered molecular ion beams, allowing for HRTEM imaging while ensuring an unambiguous identification of the observed structures. Here, our effort to correlate the observations from TEM with the deposition method by changing deposition energy and coverage can give insight into fabrication of complex 2D materials involving SLG and POM molecules that could find application in electrochemistry, catalysis and nano-magnetism [2][3]. References [1] S. Rauschenbach et al., Small, 2, 540-547, (2006) [2] N. Mizuno, M. Misono, Chemical Reviews, 98, 199-218, (1998) [3] D.-L. Long et al., Angewandte Chemie International Edition, 49, 1736-1758, (2010)

Resume : Synthesis of activated carbon from agricultural waste is gaining in interest since several years. However the different applications depend upon the final properties end precursors of activated carbons. Between the different agricultural industry by-products we can find crushed cork providing from insulation panels industry. In this work the used by-product was provided by local insulation factory at Jijel City in the north east coast of Algeria. The aim of the work is to obtain high specific surface area for heavy metals adsorption. Preliminary studies were performed on physical activation under nitrogen pyrolysis at two different temperatures (700°C and 900°C) and indicated that pyrolysis at 900°C gives higher surface areas than 700°C. However the carbons were not active for cyclic voltammetry in Vanadium electrolyte indicating that they are not glassy carbons. SEM and BET studies are running.

Resume : [Introduction] Daicel is a Japanese chemical company, which was formed through the merger of eight celluloid producers in 1919. As a part of our effort to create new business domains, we started developing the detonation nanodiamond, and have already established semi-commercial production capacity for the detonation and for purification of the detonation soot to provide nanodiamonds (ND). Addition to these, we have been developing methods for preparing nano-dispersion of ND in various kinds of solvents and other materials by modifying surface of NDs. In the talk, we will introduce some of recent topics about commercial applications DAICEL has been working on, using these surface modified NDs. [Commercial applications of NDs] Tribology : We prepared synthetic oils with very small amount of nano-dispersed NDs. When used for lubrication of metals, they lowered friction and wearing of the metal at the same time. Considering commercial feasibility of this kind of products, it is important very small amount gives big differences. Thermal stabilizer : NDs can act as “radical sponge” at high temperature, and this performance can be enhanced with suitable surface treatment. Plastics with these NDs showed higher durability especially when used at high temperature. Metal plating : Although there are many reports about co-deposition of NDs with metal by plating, obtaining truly nano-dispersed NDs in metal is almost impossible as the NDs’ zeta-potential doesn’t work in solution with high ionic strength. Polyglycerol modified NDs (PG-NDs) can be dispersed to aqueous solution with high ionic strength. Electronic metal plating of a precious metal with nano-dispersed NDs improved shininess of the metal surface and gave very small surface roughness.

Resume : Few studies were reported on the synthesis of diamond coatings on silica particles by chemical vapor deposition (CVD), leading to polydispersed and large diameters diamond coated particles. Such diamond coating on submicrometric silica particles was successfully used to build a doped diamond foam for electrochemistry [1]. We developed a reproducible and up-scalable process to synthesize monodispersed diamond core-shells dispersible in water. This technique is based on silica beads seeded with nanodiamonds exposed to a microwave CVD plasma in a set-up dedicated to the powder. The CH4/H2 ratio was optimized to improve the crystalline quality and the thickness of the coating to ensure isolated spherical particles. An ultrananocrystalline diamond (UNCD) microstructure was confirmed by Raman and SEM. Aqueous colloidal suspensions were characterized by DLS after a disaggregation step and an oxidation. The same protocol was applied to synthesize diamond coatings on silica particles hosting a magnetic core [2]. The resulting materials were characterized using TEM, Raman and SEM. This material opens the way to biomedical applications or to water depollution as well as to the synthesis of catalytically active, highly porous diamond materials. This work received funding from the European Union´s Horizon 2020 Program under Grant Agreement n° 665085 (DIACAT). References: [1] F. Gao et al., ACS Appl. Mater. Interfaces 8 (2016) 18640. [2] Georgelin et al., Angew. Chem. Int. Ed. 2010, 49, 8897.

Resume : Scaffold design and fabrication are major areas in tissue engineering. Supercritical CO2 technology offers a bio-safe fabrication route for production of 3D scaffolds. In SC-CO2 processes based on solvent elimination, SC-CO2 acts as an antisolvent for polymers. Meanwhile, efficient solvent elimination can be obtained due to the high affinity of SC-CO2 to almost all of the organic solvents. This approach can be combined with porogen leaching technique to create an additional interconnected network of appropriate size and distribution. Here, the porogen leaching and SC-CO2 assisted solvent removal are combined to prepare polycaprolactone/graphene oxide (PCL-GO) microporous structures. Moreover, ethyl lactate (EL) as a green solvent was used in the preparation of scaffolds. Apart from its benign nature, EL enabled the distribution of GO sheets homogeneously in PCL-GO, whereas, use of dichloromethane resulted in agglomoration of GO in PCL-GO structure. Low volatility restriction of EL was overcome by eliminating the solvent in a SC-CO2 assisted process. Sodium chloride particles were used as the porogen. SEM observations revealed the microporous interconnected structures of the scaffolds. Raman spectra confirmed the presence of GO in PCL scaffolds. XRD measurements showed incorporation of GO affected the crystallinity in a trivial manner. PCL-GO scaffolds did not possess any toxicity towards L-929 mouse fibroblasts and cell spreading was triggered in the presence of GO.

Resume : Nanosized diamond powders (nanodiamond or ND), produced by detonation synthesis in large volumes mainly by Russia, China, Japan, and European countries, represent a relatively inexpensive carbon nanomaterial with many unexplored capabilities and a broad range of potential applications, such as drug delivery and biomedical imaging, composite materials, lubricants, polishing and cooling liquids, etc. ND is composed of particles of ~5nm in diameter consisting of an inert diamond core with covalently bonded surface functional groups such as C=O, COOH, OH etc. In as-produced material, which usually needs to be purified prior to use, the diamond core is surrounded by graphitic shells and amorphous carbon. One of the major obstacles preventing the ability to implement ND in composite and biomedical applications is its high tendency to aggregate. In ND powders and most suspensions, primary ND particles of ~5 nm diameter form aggregates up to several micrometers in size. Existing ND de-aggregation techniques will be reviewed. We propose a simple salt-assisted ultrasonic de-aggregation technique using water soluble cheap salts such as NaCl that are hard enough to break the ND aggregates and can be easily removed from de-aggregated ND colloids by rinsing with water. The major differences and unique properties of ND compared to other carbon nanomaterials, such as carbon nanotubes, are due to its large accessible and reactive surface bearing a large variety of surface functional groups. Different surface chemistry control techniques will be discussed with emphasis on the development of 5 nm ND particles with optimal surface chemistry for biomedical applications.

Resume : 2D supramolecular self-assembly at surfaces is a good way to form well defined nanostructures on various substrates.[1] One of the current challenges is to extend this approach to 3D functional building blocks. Moreover, the robustness under ambient conditions of the assembled monolayer is also an important issue to take into account in the design of new materials. This is why we previously developed a strategy at the liquid/solid interface to steer the assembly of organic molecules on a surface using a ?molecular clips?.[2] Then, the concept of 3D Janus tecton was proposed:[3] a doubly-functionalized building block that exposes two opposite faces linked by a rigid spacer, developing chemical strategies to attach on the upper-layer different functionalities.[4] In this context, we recently addressed this issue by providing a strategy for the controlled lifting and positioning of functional units above a graphitic substrate.[5] This was the first time that multistory cyclophane-based 3D tectons incorporating C60 units have been designed and synthesized. Molecular modeling provides a description of the 3D geometries and evidences the flexible character of the building blocks. Despite this later feature, the supramolecular self-assembly of Janus tectons on HOPG yields well-ordered adlayers incorporating C60 arrays at well-defined mean distances from the surface. As our approach is not limited to C60, the results reported here open-up possibilities for applications where the topology and electronic interactions between the substrate and the functional unit are of prime importance. [1] a) Barth et al., Nature, 437, 671-679 (2005). b) De Feyter, S. et al., Chem. Soc. Rev., 32, 139-150 (2003). c) Bartels, L. Nature Chem., 2, 87-95 (2010). [2] Bléger, D., Kreher, D., Mathevet, F., Attias, A-J.et al. Angew. Chem. Int. Ed., 47, 8412 (2008). [3] Bléger et al. Angew. Chem., Int. Ed., 50, 6562 (2011). [4] a) Du, P., Kreher, D. et al. Angew. Chem., Int. Ed., 53, 10060 (2014). b) Du, P. et al., Beilstein J. Nanotechnology,, 6, 632–639 (2015). [5] Du, P., Kreher, D. et al., ChemPhysChem, 16, 3774-3778 (2015).

Resume : Polymer bonded explosives (PBX), which refer to a particle filled composite consisting of 90-95% weight of powerful explosive crystals held together by a certain amount of polymer binder, are being extensively used in energetic field. Although the content of binder in PBX is relatively small (normally 5-10%), it has definitive influence on the environmental adaptability which was more and more important. In this paper, study on the preparation of MWCNTs/fluoropolymer nanocomposite was carried out, and TATB-based polymer bonded explosive was prepared by using this new nanocomposite as binder. The research covered the influences of MWCNTs/fluoropolymer on the mechanical properties and the thermal property of TATB-based PBX. The appearance of MWCNTs/fuoropolymer was tested by scanning electron microscopy (SEM), the mechanical properties were tested by material testing machine, and the thermal property was measured by thermal conductive machine. Results indicated that MWCNTs could be significantly improved their dispersion in fluoridated polymer under the help of ultrasonic vibrations and surfactant. The essential work of fracture (We) increased with the addition of MWCNTs in fuoropolymer. The mechanical properties and thermal property were dramatically improved when 0.05g MWCNTs were added into 100 g PBX. Compared with PBX using pure fluoridated polymer, the compression strength and elongation of PBX using MWCNTs/fluoropolymer were increased by 9.0% and 16.8% respectively, the tensile strength and elongation at break were increased by 16.7% and 64.1%, and the thermal conductivity increased from 0.51 W.m-1.K-1 to 0.69 W.m-1.K-1.

Resume : Here, we report a facile approach to prepare a new class of twisted chiral nanostructures based on organic nanofiber using beta-lactoglobulin protein template. This protein possesses a unique properly of self assemble to form twisted nanofibrilar aggregates upon controlled heating at low temperature. The method involves one pot room temperature co-polymerization of 1,5-dihydroxynapthalene and 1,3,5-trimethyl-1,3,5-triazinane in aqueous system containing dispersed protein filaments, which results in π electron rich polymer coated twisted nanofiber. Electron microscopic observation performed by SEM and HRTEM clearly demonstrates morphological transcription of twisted protein fibrils (ca. 20 - 30 nm in diameter) to organic twisted nanofibers. CD and UV-visible spectroscopies indicated that heat-treated protein filaments are constructed on the basis of S-chirally ordered molecular structures in aqueous system, which was transformed in organic nanofibers. The original chiral morphology was perfectly maintained after the co-polymerization. It was believe that the enhancement of chiral ordering of protein fiber by incorporation of polymer. We demonstrated a handedness control over the chiral morphology of molecular self-assembly and stabilization of chiral structure through rapid transcription. Further the obtained twisted organic nanofilaments were subjected to carbonization at moderate temperature. A colloidal dispersion of twisted ultrashort carbon nanofibers was achieved in aqueous solution. The study demonstrated a custom design of chiral carbon nanostructures and making them promising platform for chiral optoelectronics.

Resume : Graphene Oxide Liquid Crystal (GOLC) is a newly emerging graphene based material, which exhibits nematic type colloidal discotic liquid crystallinity with the orientational ordering of graphene oxide flakes in good solvents, including water. Since our first discovery of GOLC in aqueous dispersion at 2009, this interesting mesophase has been utilized over world-wide for many different application fields, such as liquid crystalline graphene fiber spinning, highly ordered graphene membrane/film production, prototype liquid crystal display and so on. Interestingly, GOLC also allow us a valuable opportunity for the highly ordered molecular scale assembly of functional nanoscale structures. This presentation will introduce our current status of GOLC research particularly focusing on the nanoscale assembly of functional nanostructures. Besides, relevant research works associated to the nanoscale assembly and chemical modification of various nanoscale graphene based materials will be presented.

Resume : A simple study for preparing a few layered graphene by mild ball milling graphite powder in presence of N-methyl-2-pyrrolidone (NMP) with auxiliary reagents was proposed. Different adjuvants lead to different morphologies and electrochemical properties of graphene. The morphology and layer structures were confirmed using atomic force microscopy (AFM), high-resolution transmission electron microscopy (HRTEM) and Raman spectroscopy. The effects on the electrochemical behavior were discussed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) using K3[Fe(CN)6] and ferrocene as probes, revealing the differences of electron transfer efficiency and surface area owing to exfoliation efficiency. On this basis, the prepared graphene was used to modify glassy carbon electrode (GCE) to simultaneously detect different phenolic pollutants. Compared with bare GCE, the oxidation activity of graphene modified GCE is improved greatly. Based on the signal amplification of graphene nanosheets, a novel electrochemical platform with high sensitivity was developed.

Resume : The H2 concentration in expired air is known as a good indicator of disorders in small intestine. Various sensors using Pd as a sensing layer or as a catalyst on conductive materials have been proposed because Pd has high selectivity to H2. However, their characteristics are usually affected by relative humidity variations. Therefore, high temperature operations for humidity robustness have been utilized. Not only external heaters but also Joule heating (self-heating) of sensing materials have been used. However, most studies on self-heating focused on sensor response/recovery time. No attention has been paid to self-heating-induced changes in the physical properties and device parameters except for temperature. In this work, the effects of self-heating on Pd-functionalized suspended graphene sensors were investigated. Energy-efficient self-heating was realized thanks to nanoscale point contacts between the graphene and Au electrodes, which suppressed heat dissipation to the electrodes. At temperatures over 100 °C, the sensor response realized by self-heating was lower than that by external heater heating. The response reduction was due to suppressed charged-carrier scatterings with H-induced potentials under high electric fields in the self-heated graphene. This result specific to self-heated graphene helps optimization in making mobile sensors for use in health diagnosis applications.

Resume : Electrochemical applications of materials are challenging as these devices need to work in aggressive media ranging from acids to ionic liquids to physiologic buffer solutions. Most of established substrates do not possess long term chemical stability, giving rise to decomposition, poisoning and surface fouling. In addition, future technologies will require integration into electrochemical platforms like super-caps, bio-sensors, fuel cells and water-splitting devices for energy storage and conversion, for sensing and for catalytical material processing. In this presentation we will introduce diamond which can become a promising candidate for a variety of energy storage applications. Diamond shows superior properties for use in applications as indicated above. Diamond can be grown on large area in poly- or nano-crystalline form, either insulating (transparent) or metallically conductive using boron as p-type dopant. Diamond is also available as single crystalline material with superior electronic properties for membranes and high quality electrodes. Diamond electrochemical surfaces can be flat and smooth; however, by top down etching or bottom up growth, we have introduced diamond wires and foam for surface enlargements in super-caps or membranes in bio-fuel cells. The surface of diamond can be terminated with a variety of atoms or molecules to control the wetting properties (hydrophobic, hydrophilic) and to tune the electron affinity with respect to electrochemical potentials. In addition, hydrogen has been shown to terminate the surface carbon bonds close to perfect which results in an unpinned surface Fermi level which can align with the chemical potential of buffer solutions. The electrochemical potential-window of diamond is significantly larger and the background current within this regime considerably lower than conventional materials. Diamond is known to be biocompatible and has therefore a potential for “in-vitro and in-vivo” electronic applications. During recent years a variety of surface modifications have been introduced and surfaces have been functionalized with DNA, enzymes and proteins. It has been demonstrated that the bonding of bio-molecules to diamond is chemically more stable than to other substrates. In this presentation we will introduce and discuss these properties, the realization of nano-textures, nano-wires and foam using self-organized particle-formation as templates for etching or overgrowth. We will show applications of diamond in ultra-micro- and nano-electrode arrays, in scanning electrochemical microscopy tips (SECM) and in super-caps as surface enlarged electrode. We will show that diamond surfaces can be hydrogen terminated to realize fast electron exchange rates using an electrochemical schema.

Resume : Enzymatic Biofuel cells (EBC) that use glucose and oxygen as fuels are devices changing chemical energy of the fuels to electrical energy using enzyme based biocatalysts. Because the EBC can operate at low-temperature and neutral pH, glucose and oxygen included in human body fluid like blood flowing in blood vessel can be used for the purpose and implantable devices containing EBC can be realized. However, notwithstanding that, there are still issues to be disentangled. Languid reaction rate of the enzyme based biocatalyst is the main cause and thus, the difficulty should be mitigated. For doing that, the adoption of mediator into the enzyme based biocatalyst can be considered. By the use of the embedded mediator, electron transfer for both anodic and cathodic reactions is facilitated and in turn, related reaction rate is improved. In this study, we introduce mediator embedded biocatalysts. In terms of bioanode, glucose oxidase (GOx) enzyme and dye mediator are considered, while regarding cathode, GOx enzyme and porphyrin mediator are considered. Due to the employment of GOx enzyme and mediators, the catalytic activity of biocatalysts and the EBC performance are enhanced.

Resume : Long-term stability is crucial for the future application of perovskite solar cells (PSCs), a promising low-cost photovoltaic technology that has rapidly advanced in recent years. Here, we designed a nanostructured carbon layer to suppress the diffusion of ions/molecules within PSCs, an important degradation process in the device. Furthermore, this nanocarbon layer benefited the diffusion of electron charge carriers to enable a high energy conversion efficiency. Finally, the efficiency on a PSC with an aperture area of 1.02 cm2, after a thermal aging test at 85 oC for over 500 hours, or light soaking for 1,000 hours, was stable of over 15% during the entire test. The present diffusion engineering of ions/molecules and photo generated charges paves a way to realizing long-term stable and highly efficient PSCs.

Resume : Carbon dots (C-dots) are an emerging class of carbon nanomaterials with sizes below 10 nm. In recent years, they are the focus for a spectrum of environmental and energy applications, ranging from heterogeneous chemical catalysis, photocatalysis, electrocatalysis to energy storage such as batteries and/or capacitors. Here, we present an account of the recent progresses on carbon dots from our research activities [see references]. We start with an overview of the preparation methods and typical structures of C-dots, followed by a discussion of their chemical and physical properties. We focus on their environmental and energy applications, and the recent advances on the design of catalysts and functional materials based on C-dots. The following applications are demonstrated: The use of C-dots to perform as (1) photocatalysts and (2) electrocatalysts, as well as to design (3) photocatalysts, (4) photoelectrochemical catalysts, (5) electrocatalysts, and (6) nanocomposite functional materials. We will report, in details, a simple, versatile and cost-effective methodology for initiating healing in bulk polymers and self-healing and anti-corrosion properties in polymer coatings: introduction of carbon dots (CDs), 5 nm sized carbon nano-crystallites, into the polymer matrix forming a composite. The CDs are blended into poly-methacrylate (PMMA), polyurethane (PU) and other common polymers before or after polymerization. The healing/self-healing process is initiated by interfacial bonding (covalent, hydrogen and Van der Waals bonding) between the CDs and the polymer matrix and can be optimized by modifying the functional (amino, carboxyl and hydroxyl) groups which terminate the CDs. The healing properties of the bulk polymer-CDs composites are evaluated by comparing the tensile strength of pristine (bulk and coatings) composites to those of fractured composites that were healed, and by following the self-healing of scratches intentionally introduced to polymer-CDs composite coatings. The composite coatings not only possess self-healing properties, but also have superior anti-corrosion properties compared to those of the pure polymer coatings. Finally, we provide an outlook of the future development of C-dots-based functional materials. Reference: 1. Li, H. T.; He, X. D.; Kang, Z. H.;* Huang, H.; Liu, Y.;* Liu, J. L.; Lian, S. Y.; Tsang, C. C. A.; Yang, X. B.; Lee, S. T.* Angew. Chem. Int. Ed. 2010, 49, 4430–4434. 2. Li, H. T.; Kang, Z. H.;* Liu, Y.; Lee, S. T. J. Mater. Chem. 2012, 22, 24230–24253. 3. Han, Y. Z.; Huang, H.; Zhang, H. C.; Liu, Y.*; Han, X.; Liu, R. H.; Li, H. T. and Kang, Z. H.* ACS Catalysis 2014, 4, 781–787 4. Liu, J.; Liu, Y.; Liu, N. Y.; Han, Y. Z.; Zhang, X.; Huang, H.; Lifshitz, Y.;* Lee, Lee S. T*.; Zhong J.; Kang, Z. H.* Science 2015, 347, 970-974. 5. Liu, J.; Zhao, S.Y.; Li, C. X.; Yang, M.M.; Yang, Y.M.; Liu, Y.; Lifshitz, Y.*; Lee, S.-T.*; Kang, Z.H.* Adv. Energy Mater. 2016, 1502039.

Resume : Battery-like supercapacitors refer to these electrochemical capacitors (ECs) that possess the features of both ECs (e.g., high power density, P) and batteries (e.g., high energy density, E), as well as big capacitances (C) and long capacitance retention. These ECs meet the demands for powering future multifunctional electronics, hybrid electric vehicles, and industrial equipment. The construction of such battery-like supercapacitors is thus becoming the core activity of EC researches in recent years. In this presentation, the fabrication of battery-like supercapacitors by use of vertically aligned carbon nanofibers (CNFs) grown on boron doped diamond (BDD) films will be shown. These CNF/BDD based capacitor electrodes were grown by means of a thermal chemical vapor deposition technique, a copper film as the catalyst, and C2H2 as the reaction gas. These capacitor electrodes possess large surface areas, high conductivity, high stability, and importantly are free of binder. The large surface areas result from porous structures of CNF/BDD films. The containment of graphene layers and copper metal catalysts inside CNFs leads to their high conductivity. Both electrical double layer capacitors (EDLCs) in inert solution and pseudocapacitors (PCs) using Fe(CN)63-/4- redox-active electrolytes are constructed with three- and two-electrode systems. The assembled two-electrode symmetrical supercapacitor devices exhibit capacitances of 30 and 48 mF cm-2 at 10 mV s-1 for EDLC and PC devices, respectively. They remain constant even after 10 000 charging/discharging cycles. The power densities are 27.3 kW kg-1 and 25.3 kW kg-1 for EDLC and PC devices, together with their energy densities of 22.9 Wh kg-1 and 44.1 Wh kg-1, respectively. The performance of these devices is superior to most of reported supercapacitors and batteries. Vertically aligned CNFs/BDD hybrid films are thus useful to construct high-performance battery-like and industry-orientated supercapacitors for future power devices.

Resume : Thanks to their unique electrical properties and high surface area leading to high sensitivity, nanocarbons (graphene, carbon nanotubes (CNT) etc.) are considered as excellent candidates for gas sensor applications. Because of their surface chemistry and high adsorption capacity, pristine nanocarbons are sensitive to a wide range of gas molecules. Nevertheless, they suffer from moisture sensitivity, a lack of selectivity and slow desorption rate leading to higher recovery time. These drawbacks limits their applications for gas sensing. To favor their application in the field of sensors, nanocarbons are functionalized with semiconducting metal oxides, conductive polymers and so on. In this context, we have opted for the conductive polymer, especially polyaniline, which is another type of sensitive material widely studied, due to its high sensitivity, unique electrical properties, environmental stability and easy manufacturing process. The use of these composites polymer / nanocarbon demonstrates attractive detection properties and induces a considerable increase in the sensitivity of the sensors. This functionalization modifies the surface chemistry of nanocarbons and creates an interaction of the two materials by charge transfer. The presentation will focus on sensing performances of such hybrid materials by arguing the role of surface modification on nanocarbon materials in gas sensing at room temperature. The sensing materials will be structurally characterized by UV-vis spectroscopy, FT-IR spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM).

Resume : For this research, the new electrochemical and colorimetric analysis methods are introduced to evaluate how much the phosphoric acid ion poisoning is proceeded on the surface of platinum (Pt) based catalyst to prove whether the method can replace the drawbacks of conventional methods that are very expensive and take long time to be measured. For employing the new methods, the half cell tests, such as cyclic voltammetry (CV) and linear sweep voltammetry (LSV) are performed and the variances in chemical behavior by (i) poisoning of the phosphoric acid ion on surface of Pt based catalyst and (ii) hydrogen peroxide decomposition reaction are properly detected by the new colorimetric measurements. Based on that, it turns out that the new electrochemical and colorimetric analysis methods are sensitive enough for measuring precisely the degree of phosphoric acid poisoned on Pt based catalyst.

Resume : Graphene, bi-dimensional form of graphite, is characterized by its unique chemical, optical, electrical and thermal properties. The synthesis method, the number of layers, and -foremost- the type of substrate are the key factors that determine these properties. Every application of graphene requires the transfer from the transition metals on an appropriate substrate, chosen in function of the desired application. Monolayer graphene is obtained by Chemical Vapour Deposition (CVD) on the cooper substrate and is then transferred on the gold substrate. Graphene/substrate interaction induces modifications in the arrangement of carbon atoms. The characterization of surface morphology will be performed by Scanning Electron Microscopy (SEM), while that of structure’s type and substrate’s influences on the defect can be determined by means of Raman spectrometry. X-ray diffraction (XRD) and Raman spectrometry confirm the presence of graphene after transfer. The Raman spectra show the differences of the graphene features in function of the substrate. On the gold substrate, graphene has proven outstanding plasmonic properties, resulting in an improvement of its optical properties. The obtained results displays the great potential for medical devices, special for the theranostics domain.

Resume : Nowadays lithium-ion hybrid supercapacitors (LIHSs) by virtue of a higher energy density and longer cycle life by the electrical and electronic industry wide attention. Because LIHSs special assembly method[1], it combines the lithium-ion battery and supercapacitor energy storage advantages. However LIHSs still face many challenges, such as poor rate capability, limited long-term cycling stability and so on[2]. Lithium vanadium phosphate (Li3V2(PO4)3) is the one of has great potential in the future Electrode material[3]. In this work, we find that Li3V2(PO4)3 is the three-dimensional (3D) network, because of this special structure will make the phase body space of Li3V2(PO4)3 expand, reduce the resistance of the intercalation/de-intercalation of cations (e.g. Li+) in the bulk of active materials. However the phosphate family has been known to have poor conductivity[4]. We prepared the carbon-coated Li3V2(PO4)3 by improved the sol-gel method, formed LVP nanoparticles embedded into carbon nanofilms. As a cathode material it exhibit high specific capacity of 124mA h g-1, even at higher rate it also retain specific capacity of 94 mA h g-1 and the better rate performance. With activated carbon as the negative electrode were assembled into LIHSs, showing a capacity retention of over 71% after 1000 cycles at 500mA g-1, even after 5000 cycles, the specific capacity can still maintain 61%. Compared with the symmetrical capacitor, this work LIHSs have several orders of magnitude higher energy density than symmetrical capacitors at the same power density. Reference [1] Sun F, Gao J, Zhu Y, et al. A high performance lithium ion capacitor achieved by the integration of a Sn-C anode and a biomass-derived microporous activated carbon cathode[J]. Scientific Reports, 2017, 7. [2] Ma Y, Chang H, Zhang M, et al. Graphene‐Based Materials for Lithium‐Ion Hybrid Supercapacitors[J]. Advanced Materials, 2015, 27(36): 5296-5308. [3] Rui X, Yan Q, Skyllas-Kazacos M, et al. Li3V2(PO4)3 cathode materials for lithium-ion batteries: a review[J]. Journal of Power Sources, 2014, 258: 19-38. [4] Satish R, Aravindan V, Ling W C, et al. Carbon-coated Li3V2(PO4)3 as insertion type electrode for lithium-ion hybrid electrochemical capacitors: An evaluation of anode and cathodic performance[J]. Journal of Power Sources, 2015, 281: 310-317.

Resume : First-principles electronic structure calculations are a powerful tool to elucidate microscopic details of structures. The progress in the first-principles modeling of structures and processes in electrochemical energy storage and transfer is strongly linked to the advances in experimental techniques, and it requires a close collaboration between theory and experiment. Carbon materials are used as electrode materials in supercapacitors, due to high electrical conductivity, low cost and availability at ease. In this work, we utilized first-principles electronic structure calculations, which based on the Density Functional Theory (DFT), the one-dimensional (1D) nanomaterials of carbon nanotubes (CNT) and two-dimensional (2D) graphene oxide (GO), carried out band gap values of 0.500 eV and 3.328eV, respectively. Reduced graphene oxide (RGO) has an turnable band gap. Furthermore, we also investigated, by means of experiments, that the electrochemical performance of RGO is better than CNT and GO. Theoretical prediction and experimental validation displayed that rGO will become the remarkable supercapacitor materials，owing to (1) avoid π-π stacking and van der Waals interactions; (2) the application of electrochemical controlled by adjusting content of oxygen;(3) contain tiny amounts band gap can vastly enhance the potential in various applications.

Resume : A novel electrochemical sensor for selective detection of p-aminophenol (p-AP) was fabricated using hemin-graphene (HG) composites and molecularly imprinted polymer (MIP). The morphology and FT-IR spectra of the prepared MIP were characterized and the electrochemical property of modified electrodes was investigated. The results indicated that HG composites promoted the electroreduction process of p-AP on electrode while the p-AP-binding MIP was able to selectively accumulate the analyte on the electrode surface. Under optimized conditions, the reduction peak current of the fabricated sensor increased linearly with the concentration of p-AP in the range from 0.3 ~ 25 μM with a detection limit (S/N = 3) of 0.06 μM. Moreover, the developed sensor exhibited high selectivity and good reproducibility for p-AP detection.

Resume : Gold nanoparticles (Au NPs) and graphene-doped CdS (GR-CdS) were employed to fabricate a photoelectrochemical (PEC) aptasensor for detection of diclofenac (DCF). It was observed that GR-CdS modified electrode exhibited a high and stable photocurrent response upon visible light illumination, due to the excellent electrical and optical property of GR as well as the high absorption efficiency of CdS in the visible region. While Au NPs were incorporated with GR-CdS, a further increase in photocurrent response was observed owing to surface plasmon resonance. Moreover, the Au NPs were advantageous to immobilize the SH-terminated aptamer used as a biorecognition element. Upon interaction of DCF with the immobilized aptamer, the DCF molecules were captured by the aptasensor. When the sensor was illuminated with visible light, an enhanced PEC current response to DCF was realized due to the oxidation of the captured DCF by the photogenerated holes. Under the optimized conditions, the sensor showed a PEC response linear to DCF concentration in the range of 1 to 150 nM, with a detection limit (3S/N) of 0.78 nM. Thus, a highly selective and sensitive PEC sensor for the determination of DCF was provided.

Resume : Plasma treatment of porous materials has potential in many applications where chemical modification of interior structure or its loading nanoparticle with supports is required. The novel effects of the plasma treatment on the microstructural and surface properties of the porous materials. Activated carbon (AC) based materials for catalysis are currently attracting tremendous attention due to their unique and advantageous properties. However, the application in gas-phase thermal catalysis including the catalytic oxidation of volatile organic compounds (VOCs) remains a selectively efficiency, life time, and low capacity of AC. In this work, a plasma-assisted method was employed to prepare a Mn/Ag catalyst on the surface and pore of activated carbon for formaldehyde (HCHO) oxidation. We presented a Mn/Ag catalyst with enhanced elimination efficiency by a surface modification strategy of plasma treated activated carbon functionalization. The HRTEM, SEM, TGA and XRD results confirmed the exposed conditions of the Mn/Ag and the sizes (< 100 nm) of the Mn/Ag catalyst with loading amounts close to 7%. The plasma power reduced the sizes of the Mn/Ag nanoparticles and enhanced support interaction, which enhanced the catalytic performance. Therefore, activated carbon functionalization is obtained through plasma treatment, which demonstrates the high versatility of the plasma fabrication for developing green process and efficient catalysts.

Resume : Laser-induced graphene (LIG) from polymers provides a simple approach to the direct construction of conductive carbon patterns on insulative substrates for cost-effective electronic devices, which have promising applications in a wide range of fields. Currently, several polymers have been reported for the preparation of LIG, including PI, PEEK, phenolic resin and wood, which however generally exist in the form of solid blocks or films. Here, we demonstrated that PVDF is also a promising precursor of LIG. Different from other precursors, PVDF may exist in the form of flexible and porous membranes, thus enabling the direct construction of conductive and porous carbon arrays on PVDF membranes by laser scribing. Moreover, the infiltration of the PVDF-based LIG arrays with Nafion allows the construction of smart paper-like humidity sensor with the advantages of simple structure, rapid response and high sensitivity, which can be used for the real-time humidity monitoring of expiratory air from both nose and skins.

Resume : As a growing portion of the focus into wearable sensing is dedicated to medical sciences and the monitoring of physiological activities, new advances are being made to enhance the performance and functionality of wearable sensors. The proposed sensor system will detect small molecules from the user or their surrounding environment which pose a threat to health and safety, and will be worn close to or on the surface of the skin. Due to the location of the sensors, the sensor design must take into account the non-linear nature of the body. As a result, the sensor system must consist of materials whose high functionality and performance are preserved while subject to deformation. For this reason, the application of ionic liquids into the sensor design is pivotal. Several ionic liquids will be evaluated in order to examine which would provide the greatest chemical window. The utilised ionic liquids will be enhanced depending on the choice of analyte. Once the optimal analyte has been chosen of three gaseous analytes (eNO, H2S and CO), along with the optimal choice of IL and electrodes, the sensor design will be scaled down. As a result, the properties of the electrodes will be enhanced by making use of nanoparticles (e.g carbon nanotubes, graphene, etc) or even ionic liquids, by adopting them as coatings or standalone electrodes. The sensor architecture may be modified similarly to maximise both the robustness of the sensor and the output signal produced from the input stimuli.

Resume : All of recent years, PEDOT has attracted wide attention because of its good conductivity, low redox potential, good thermochemical stability, easy film formation and good biocompatibility. The various applications have been developed on its Electronic devices and chemical properties. Carmine is a synthetic food additive, and has some toxic side effects to human bodies. In view of the widespread existence of Carmine and its harmfulness, to establish an efficient, fast, accurate, simple and economical method to detect Carmine is very necessary. In this paper, a high sensitivity and quantitative detection of Carmine molecularly imprinted membrane sensor was successfully constructed .Enhanced electrode conductivity was achieved sequentially by constructing a conductive polymer (PEDOT: PSS) on a screen-printed carbon electrode (SPCE), followed by electrode position with gold nanoparticles (AuNPs) and, finally, by modification with positively charged ß-Mercaptoethylamine (CA) using an Au–S bond. The main content of this work: (1) Preparation PEDOT: PSS, HAuCl4 and CA solution. PEDOT: PSS and HAuCl4 solution were sequentially electropolymerized onto the electrode, and then the modified electrode was placed in CA solution for self-assembly. (2) Molecularly imprinted polymers (MIP) are prepared by thermal priming, trimethylolpropanetrimethacrylate (TRIM) as cross-linking agent and azobisisobutyronitrile (AIBN) as initiator. Non-molecularly imprinted polymers (NIPs) were prepared in the same procedure, with no addition of the template molecule. The polymer prepared above was ultrasonic elution in methanol acetic acid solution, then vacuum dried. The prepared molecularly imprinted polymer was coated on the PEDOT/PSS/AuNPs/CA functionalized screen-printed carbon electrode. (3) The adsorption ability of MIP was evaluated by absorbance change of solution after adsorption. Polymerization parameters were optimized by electrochemical performance evaluation of MIP using differential pulse stripping voltammetry (DPV). (4) The surface and the molecular structure of the modified electrode were characterized by Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Spectroscopy (EDX), X-ray photoelectron spectroscopy(XPS). The basic electrochemical properties of PEDOT/PSS/AuNPs/CA/SPCE were studied by means of CV, Electrochemical Impedance Spectroscopy (EIS) and differential pulse stripping voltammetry (DPV). (5) In the context of the optimal experimental parameters, the carmine molecularly imprinted electrochemical sensor sensitivity has been researched. In addition, the specificity, the real sample detection and the stability of the manufactured imprinted sensor were evaluated. The linearity range and the detection limit were obtained as 9.5 x 10-8 to 3.5 x 10-6M and 25.87nM. There are many advantages in this method, such as strong specificity, low cost, simple operation, short test time, which is expected to provide a rapid, accurate and sensitive detection method for food safety supervision.

Resume : The chemistry of porous, crystalline coordination polymers (PCPs), also called metal-organic frameworks (MOFs), has been paid much attention on the way to large-scale industrial applications such as gas storage, drug delivery, catalysis and sensors. By designing functional organic ligands and selecting appropriate metal ions, MOFs with special functions can be fabricated. Herein, an organic compound with large conjugated system was used as ligand to prepare a MOF by using rare earth metal ion as center cation. Meanwhile, graphene oxide nanosheets were doped into the process for MOFs preparation, thus to produce a graphene oxide-MOFs nanocomposite (GrO-MOFs). The photoelectrochemical responses of MOFs and GrO-MOFs were investigated. It was found that graphene oxide can improve the photocurrent of MOFs significantly. References [1] Zhan W. W., Kuang Q., Zhou J. Z., Kong X. J., Xie Z. X., Zheng Z. X., J. Am. Chem. Soc. 2013, 135, 1926-1933. [2] Zhang K., Xie X. J., Li H. Y., Gao J. X., Nie L., Pan Y., Xie J., Tian D., Liu W. L., Fan Q. L., Su H. Q., Huang L., Huang W., Adv. Mater. 2017, 29, DOI: 10.1002/adma.201701804. [3] Aijaz A., Karkamkar A., Choi Y. J., Tsumori N., Ronnebro E., Autrey T., Shioyama H., Xu Q., J. Am. Chem. Soc. 134 (2012) 13926-13929

Resume : Various nanocarbons such as graphene, carbon nanotubes, and expanded graphite have been widely employed for electrochemical applications. Due to their different morphology and surface functional groups, they actually feature different electrochemical properties. However, the comparison of electrochemical properties of these nanocarbon is seldom reported. Herein, electrochemical properties of several nanocarbons including graphene nano platelets (GNPs), multi-walled carbon nanotubes (MWCNTs), graphene oxide (GO), aminated graphene (NH2-G), expanded graphite (EG) have been studied together with their composites of EG. Reversible and diffusion-controlled electrode processes for faradaic reactions of Fe(CN)63-/4- are seen on all these electrodes. The capacitive current of MWCNTs is the biggest, while that of GO is the smallest. The composites of EG with nanocarbons feature bigger active areas than nanocarbons but smaller capacitive currents. Moreover, the electrochemical sensing applications of these nanocarbons and composites are examined as case studies. Voltammetric response of positively and negatively charged inorganic ions (Pb2+, NO2?) as well as neutral organic colorants (sunset yellow and tartrazine) has been studied on these nanocarbons and their composites. The sensitive monitoring of three species has been realized on different nanocarbons or composites. Such a phenomenon is intercepted by different interactions of charged or neutral target species with nanocarbons or the composites. This study provides a systematic investigation of electrochemistry of nanocarbons and their composites. It is thus of significance to explore different electrochemical applications of these nanocarbons and their composites.

Resume : Graphene nano platelets (GNPs) or nano graphene platelets (NGPs) are stacks of graphene sheets with an overall thickness ranging from an average of about 5 to about 25 nm. Most of them have "platelet" morphology with a diameter of 0.5 to 25 μm. Their aspect ratios are high and can be range into the thousands. They show similar thermal and mechanical properties to CNTs but their surface areas or aspect ratios are higher. They have therefore different properstes from single or few (up to 5) layered grapheme. They have been more widely applied for various applications, such as electrochemical detections and biochemical sensing. However the properties are expected to be different from. In this presentation, we will show first electrochemical properties of GNPs, including their potential windows and voltammetric response towards redox species. Then functionalization of GNPs with different surface groups (e.g., NH2-, nitrophenyl, etc.), gold nanoparticles, and gold-palladium nanoparticles (AuPd NPs) will be shown. Detailed characterization on these functionalized GNPs will be given. Electrochemical sensing applications of GNPs and these functionalized GNPs will be summarized in the last session, including direct oxidation of endocrine disrupting chemicals by use of GNPs, electrochemical oxidation of hydrazine by use of AuPd NP functionalized GNPs, voltammetric monitoring of 4-Nonylphenol by use of Au NP functionalized GNPs, electrochemical sensing of charged and no-charged targets by use of GNPs functionalized with aryl diazonium salts.

Resume : Liquid fuels such as alcohols, aldehydes, and carboxylic acids are possible sources for fuel cells. However, electrochemical oxidation kinetics of these liquid fuels is pretty slow. Namely, electrocatalysts are required to accelerate these sluggish reactions. On the other hand, catalyst support with large areas and highly active catalysts play key roles in the electrocatalytic oxidation of liquid fuels. Carbon natures as well as the nanocomposite of expanded graphite and multi-walled carbon nanotubes (EG-MWCNT) were then employed as the catalyst support due to its large electrode area. Palladium nanoparticles (Pd NPs) and the composites of Au/Pd NPs electrodeposited were utilized as the electrocatalysts. The synthesized electrocatalysts were characterized with scanning electron microscopes, transmission electron microscope, X-ray diffraction, energy-dispersive X-ray spectroscopy, and electrochemical techniques. Especially, electrochemical activity and double-layer capacitance of the Pd-NP/EG-MWCNT electrocatalysts with different EG-to-MWCNT mass ratios were investigated to optimize their compositions. Electrocatalytic oxidation of alcohols (methanol, ethanol, ethylene glycol), carboxylic acids (formic acid), and aldehydes (formaldehyde) by use of Pd and Au/Pd electrocatalysts was studied in alkaline media. On both electrocatalysts, their oxidation currents are stable and in the order of formaldehyde > formic acid > glycol > methanol > ethanol. The oxidation processes of these fuels follow two steps: oxidation of freshly chemisorbed species in the forward scan and then in the reverse scan the oxidation of the incompletely oxidized carbonaceous species formed during the forward scan. These electrocatalysts are thus useful for the facilitation of direct methanol fuel cells.

Resume : Metal-Organic Frame (MOFs), as a new type of crystalline porous materials, attracted widespread concern of researchers. MOFs are formed by the linkage of metal ions (or clusters) with organic ligands through coordination bonds. MOFs provide structural diversity, flexibility, high porosity, large surface area and a variety of pore sizes. They have shown incredible potential in the fields of catalysis, sensors, separation, gas storage and others. UiO-66-NH2, as an excellent one of these MOFs, shows huge potential for adsorbing heavy metal ions, radionuclides and organics from water or organic solvents, by taking advantages of its huge specific surface area, unprecedented thermal and chemical stability. However, its application is limited by the poor conductivity and instability. In this regard, some researchers have found that modifying some conductive polymers on the surface of electrodes can obviously improve the conductivity of MOFs and improve the sensitivity. In electrochemical sensor technology, some nanoscale conductive materials are favored for their interesting electrochemical properties, such as polymer conducting molecular wires, chemical sensors, biosensors, and light-emitting and electronic devices. In a large number of conductive polymers, the self- doped polyaniline (SPAN), which is copolymerized with aniline (AN) and amido sulfonic acid (SAN), has the advantages of high conductivity, large specific surface area and good hydrophilicity. Therefore, self-doped polyaniline (SPAN) composite is suitable for building electrochemical sensors. Due to the extensive use of heavy metals, heavy metal pollution is an important topic in today's world. In particular, cadmium is one of the most polluting heavy metals and cannot be degraded by microorganisms in a short period of time. In addition, the accumulation of these metals in the human body can cause serious diseases to human organs such as the kidney, liver, central nervous system and bone. Therefore, the establishment of a rapid detection of cadmium ions is particular significant to public health and environmental pollution control. In this work, we present preparation and sensor’s application of UIO-66-NH2@SPAN composite material prepared by loading SPAN onto the surface of MOFs. Using square wave anodic stripping voltammetry (SWASV), the detection of cadmium ions by UIO-66-NH2@SPAN shows very high sensitivity, selectivity and reproducibility. The main content of this paper: (1) Preparation of UIO-66-NH2 and SPAN. Afterwards, the UIO-66-NH2 and SPAN were mixed drop-wise onto the glassy carbon electrode and the modified electrode was then dried under an infrared heat lamp (UIO-66-NH2@SPAN). (2) UIO-66-NH2@SPAN membranes were evaluated by cyclic voltammetry (CV) and impedance (EIS) to analyze and optimize parameters that affect sensor performance. Working electrode was UIO-66-NH2@SPAN//GCE electrode, reference electrode was Ag/AgCl electrode and the auxiliary electrode was a platinum electrode. (3) Based on the square wave anodic stripping voltammetry, the capture ability of UIO-66-NH2@SPAN on cadmium ions was evaluated by simulated wastewater. (4) The surface and the molecular structure of the modified electrode were characterized by Scanning Electron Microscope (SEM), transmission electron microscope (TEM), Thermogravimetric Analysis (TGA), X-ray diffraction (XRD) and Fourier Transform Infrared Spectrometer (FT-IR). The basic electrochemical properties of UIO-66-NH2@SPAN/GCE were studied by means of CV, Electrochemical Impedance Spectroscopy (EIS) and square wave anodic stripping voltammetry (SWASV). (5) The electrochemical sensor (UIO-66-NH2@SPAN/GCE) performance was calibrated using the SWASV technique in the context of the best experimental parameters. In addition, the specificity, availability and stability of the fabricated sensors were evaluated. In addition, the stability and reproducibility of the prepared molecularly imprinted electrodes were investigated. The excellent long-term stability and repeatability of the prepared UIO-66-NH2@SPAN electrode make it attractive in electrochemical sensors.

Resume : It’s well known that bismuth-based (Bi-based) semiconductor photocatalysis usually has narrow band gap, which makes it can be excited by visible light. Recently Bi-based materials have been extensively applied in the field of environmental protection and energy. As one of the excellent photocatalysts, Bi2MoO6 has been widely applied in the degradation of organic contaminants. However, the high recombination rate of photogenerated electron–hole pairs and the low visible light-driven activity retard its applications. To overcome these problems, many approaches have been developed, for example, establishing heterojunction via loading cocatalysts. Herein, we prepared a flower-like reduced-graphene-oxide (rGO)/Bi2MoO6 heterojunction by one-pot solvothermal process. The photocatalytic experiments for degradation of organic contaminants demonstrated that rGO/Bi2MoO6 exhibits an enhanced photocatalytic activity, compared to pure Bi2MoO6.The transient photocurrent responses experiments also indicate that rGO can effectively improve the separation and transfer rate of the charge carriers of Bi2MoO6 in the photoredox processes. *Corresponding author. E-mail address: wangyychem@163.com References [1] Xiangchao Meng, Zizhen Li, Haoming Zeng, Jie Chen, Zisheng Zhang, Appl. Catal. B, 2017, 210: 160–172. [2] Xiangchao Meng, Zisheng Zhang, J. Catal., 2016, 344: 616–630. [3] Yun Hau Ng, Akihide Iwase, Akihiko Kudo, Rose Amal, J. Phys. Chem. Lett. 2010, 1: 2607–2612. [4] Nan Zhang, Min-Quan Yang, Siqi Liu, Yugang Sun, Yi-Jun Xu, Chem. Rev. 2015, 115: 10307-10377.

Resume : Metal-organic frameworks are great candidates for various applications. In electrochemistry related fields, their poor conductivity and stability somehow hindered their applications. Tp solve these problems, chromium terephthalate metal-organic framework/reduced graphene oxide (MIL-101(Cr)@rGO) materials were prepared through a simple chemical reduction method. The morphology, structure and properties of the obtained composite were first characterized by scanning electron microscopy, transmission electron microscopy, Raman, Brunner-Emmet-Teller and electrochemical techniques. The successful reduced graphene oxide coating in the MIL-101(Cr)@rGO improves the electronic conductivity of MIL-101(Cr) effectively. As a case study of electrochemical sensing applications of metal-organic frames, MIL-101(Cr)@rGO nano composite have been applied to construct the MIL-101(Cr)@rGO coated electrode and further used for the determination of 4-nonylphenol (4-NP). The results demonstrated that the electrochemical signals and peak profiles of 4-NP was significantly improved by the modified material, benefit from the synergistic effect from high conductivity of rGO and large specific surface area of MIL-101(Cr). By applying differential pulse voltammetry, the monitoring of 4-NP in the range of 0.1 μM to 10 μM was realized. The detection limit was 10 nM. This novel electrochemical sensor is thus promising for the environmental monitoring of 4-NP in future. Integrating graphene oxide into metal-organic frameworks is thus a promising way to extend the applications of metal-organic frameworks into different electrochemical fields.

Resume : Reduced graphene oxide has received widespread attention, due to abundant presence of active defect-sites and functional groups on the sheet. However, the increases of the resistance and van der Waals force during the reduction process limit the practical applications of reduced graphene oxide in supercapacitors. Herein, a rapidly, low-cost and reliable method of constructing three-dimensional Reduced Graphene Oxide (3D RGO) via using candle-soot-derived carbon nanoparticles, which serve as a template embed into reduced graphene oxide layers. Based on the first-principles of electronic structure calculations, both theoretical prediction and experimental validation displayed that 3D RGO structure is more stable and of enhanced excitation of charge carriers to the conduction band. The constructed 3D RGO resolved the issues of impedance and π-π stacking, and exhibit remarkable electrochemical performance. The 3D RGO demonstrated specific capacitance of 312 F g-1 at the current density of 0.5 A g-1, and a long-term cyclic stability (retaining 94.2% of capacitance after 10,000 cycles). In addition, , 3D RGO exhibited an excellent structural advantage as a symmetric supercapacitor. A further high-level energy density of over 52.9 Wh kg-1 with a large power density of 355 W kg-1was also obtained.

Resume : Removing of toxic compounds containing, in particular M(VI)O42- (M(VI)= Cr, Mo, W), from domestic water and industrial wastewater is an urgent technological need. Nanotechnology has many successful applications in different fields but recently its application for water and wastewater treatment has emerged as a fast-developing and promising area. Chemical functionalization of carbon nanostructures, in particular carbon nanotubes (CNTs), modifies their physical and chemical properties and leads to improvement of their performance for specific applications. Theoretical modeling of such molecular adsorption on the CNTs surfaces is a powerful tool which allows to predict some important properties of materials perspective for mentioned use. The adsorption characteristics of M(VI)O42- (M(VI)= Cr, Mo, W) molecular oxyanions on the surfaces of pure and N/B-doped CNTs and graphene sheets were studied. Graphene sheets were considered as model approximation for large-diameter CNTs. The CNT(5,5) with several surface groups including –COOH, –COO-, –OH and –NH3+ were also considered as adsorbents in order to study the influence of functionalization on the adsorption properties of the CNT-based materials with respect to toxic anions of hexavalent chromium Cr(VI). DFT-based geometry-optimized calculations of the electronic structures of carbon nanostructures with adsorbed oxyanions were carried out by Gaussian 09 program package [1]. Binding energies, relaxed geometries, charge states of the adsorbates and the electronic wavefunction profiles were calculated and analyzed. Effects of water solvent on studied adsorption surfaces were considered in a model of polarizable continuum. Adsorption mechanism was illustrated by dependence of the binding energy on the tube - molecule oxyanions distances. Calculation results were discussed in view of potential application of the CNT-based materials as efficient adsorbents of toxic oxides of hexavalent metals. [1] M.J. Frisch, G.W. Trucks, H.B. Schlegel, et al. // Gaussian 09 (Gaussian, Inc., Wallingford, CT, 2009).