Carbon materials: surface chemistry and biomedical applications

Resume : Comparison of Raman spectroscopic results is an important aspect of process and device up-scaling engineering for electrochemical energy conversion, especially when more performing ta-C coating materials have to be produced considering its unique outstanding properties. However, Raman spectra achieved with different kinds of carbon materials have shown how much contradictory and confusing those can be when not sufficiently taking into account recently discussed sp3 atomic rearrangement activation effects, the more detailed incidence of stress and material disorder on Raman assignment and some newly revised aspects on Raman fundamentals with which the origin of the so called “D disorder” and so called “2D” peak can be more accurately described. However, this is a matter which is made worse with the number of confusing denomination used for the assignment of carbon material Raman spectra especially involving the denomination “D” for diamond, “D” for disorder, “D disorder” peak which is used in relation with the graphene A-edge vibration mode, (corresponding to a well ordered crystalline structure) and some Raman peak broadening due to second order atomic disorder involving a statistical distribution of interatomic distances, binding energies, and bond orientations. The necessity of clarification on Raman peak designation appears all the more, since different side shoulders of the “G” peak can be assigned to some aliphatic bonds, atomic point defects and so called “odd rings” in consequence of used elaboration process producing point defects by ion bombardment, thermal effects and different kinds of atomic rearrangements. Therefore, we propose a new Raman designation nomenclature with which it is intended to reduce confusion and to provide more accurate characterizing of carbon material which especially appears necessary for carbon process optimization during carbon coating engineering.

Resume : For many applications it is essential to modify the electronic properties of graphene in a controlled fashion. This can be achieved via oxygen and nitrogen functionalisation in ultra-high vacuum, leading to a system in which electronic and structural properties can be systematically studied. Here we present insights from density functional theory (DFT) calculations on nitrogen and oxygen functionalised graphene systems, such as the low-energy configurations and simulated transmission electron microscopy (TEM) images, binding energies and effective band structures (EBS) of the N and O decorated graphene sheets. We directly compare our results with experiments on graphene grown by chemical vapour deposition (CVD). Angle-resolved photoemission spectroscopy (ARPES - performed at the Antares beamline of Synchrotron SOLEIL, France) resolves the band structure changes on functionalisation, simulated TEM images assist in interpreting low-voltage aberration-corrected TEM measurements, and X-ray photoelectron spectroscopy (XPS) provides information about the chemical environment of the defect atoms. Combined, the computational and experimental techniques provide valuable insights into the effect of functionalisation on the physical and electronic structure of graphene.

Resume : We present an overview of our studies on the synthesis and investigation of water-soluble fullerene derivatives (WSFs). Chlorofullerenes C60Cl6 and C70Cl8 were shown to be ideal precursors for synthesis of various WSFs. Friedel-Crafts type reactions led to big families of C60 and C70 derivatives bearing appended fragments of arylalkylcarboxylic and aryloxyalkylcarboxylic acids [1-2]. Novel reactions with amines, amino acids [3], thiols, thioacids [4] and trialkylphosphites [5] produced new classes of WSFs. Toxicity and different types of biologycal activity of the prepared WSFs will be discussed. Particular attention will be paid to antiviral activity. It is commonly accepted that anti-HIV action of WSFs is related to the HIV protease inhibition. We will prove with many examples that this belief is not correct in many cases and real target is gp120 which is inhibited efficiently by WSFs. Moreover, examples of WSFs demonstrating appreciable activity against >10 different viruses confirm great potential of using water-soluble nanocarbon materials in biomedicine and drug design. 1 O. A. Troshina, P. A. Troshin, J. Balzarini, et. al. Org. Biomol. Chem., 2007, 5, 2783 2 A. B. Kornev, J. Balzarini, P. A. Troshin et. al., Chem. Commun., 2011, 47, 8298 3 A. B. Kornev, A. A. Kushch, P. A. Troshin et. al. Chem. Commun., 2012, 48, 5461 4 E. A. Khakina, J. Balzarini, P. A. Troshin, et. al. Chem. Commun., 2012, 48, 7158 5 E. A. Khakina, P. A. Troshin et. al. Chem. Commun., 2012, 48, 8916

Resume : Regioselective cycloaddition of admantylidene carbene (1) to Pr@C2v(9)-C82 affords the first derivatives of praseodymium-containing metallofullerenes. Two monoadduct isomers (2a and 2b) were obtained. X-ray crystallographic results of 2a confirm a [5,6]-open structure with multiple metal positions. Theoretical calculations reveal that the negative charges immigrated from the internal metal ion is anisotropically distributed on the cage surface, making one of the cage carbons, which is very close to the metal ion, much more reactive than others. Our study has shed new light on the chemical behaviors of mono-EMFs which are viewed as the simplest prototypes of EMFs. Thus the results will stimulate further investigation on the formation mechanism, the properties and potential applications of these hybrid materials

Resume : The doping of 2D materials, such as graphene, which influences their electronic and chemical properties, is currently a critical aspect in their development. For example, the N-doped graphene has been reported to exhibit superior performance over the pristine material in several applications (field-effect transistors, batteries, fuel cells, super-capacitors, and biosensors). However, methods to realize a reliable and controlled doping have still to be mastered. In this work, we present an effective, versatile plasma-based method for the nitrogen-doping of graphene grown on 6H-SiC(0001). By using a tunable hybrid plasma source, we expose graphene monolayers to a stream of N ions and/or to a neutral flow of thermalized N species. The electronic properties of the N-doped graphene are revealed using angle-resolved inverse photoemission spectroscopy (ARIPES), which reveals its doping level through the analysis of the pi* states dispersion. The results show that low-energy N ions (5~35 eV) cause a n-type doping (up to 0.4 eV) with a majority of graphitic (substitutional) N (up to 8.7%), as revealed by XPS. On the other hand, neutral N species rather form pyridinic-N in the presence of defects. In brief, we show how a simple plasma-based technique can be used in a versatile way to control the bonding environment of N atoms in graphene. It will certainly be of great interest for the processing of future graphene-based nano-devices using widespread technologies like plasma-processing.

Resume : The mechanical and antibacterial properties of silver doped diamond-like carbon (Ag-DLC) films have been investigated. Ag-DLC were deposited on silicon (Si 100) and titanium substrates (Ti-6Al-4V) by pulsed laser ablation (PLD) for laser energy density 10 J∙cm-2 using KrF excimer laser and segmented target (graphite : silver - 7:1, 3:1, 5:3). The composition was analyzed using wavelength-dependent X-ray spectroscopy. The topology and surface properties as roughness of films were studied using scanning electron microscopy and atomic force microscopy. Mechanical properties of DLC films with various silver content were evaluated. Hardness (reduced Young's modulus) was determined by nanoindentation. Films adhesion was studied using scratch test and with concentration of silver decreasing. In vivo measurement (using gram positive and negative bacteria) of antibacterial properties of the Ag-DLC films. This result opens further possibility for application of Ag-DLC films in medicine.

Resume : The ability of surfaces to resist the unspecific adsorption of proteins is thought to provide an important indication about the ability of such surface to resist biofouling Therefore, there has been great interest in the development of coatings or surface modification strategies that allow controlling protein adsorption. We have recently reported on the use of aryldiazonium salt chemistry as a one-step, solution-based method for the glycosylation of carbon surfaces, leading the formation of strongly bound carbohydrate adlayers. Here we report a detailed study of protein adsorption at carbohydrate-modified amorphous carbon surfaces (a-C) using a combination of spectroscopic and contact angle methods. The adsorption of three proteins, bovine serum albumin (BSA), lysozyme (Lyz) and fibrinogen (Fib), from buffer saline solution was investigated using surfaces coated with four different monosaccharides. We show results indicating that the carbohydrate layer significantly reduces surface protein adsorption, particularly in the case of protein concentrations close to physiological values in biologically important fluids (e.g. serum). Surface energy determinations using the OWRK model suggest that changes in surface energy are partly at the origin of the observed antifouling behaviour. Finally, we also show that coatings obtained using more structurally complex carbohydrate aryldiazonium precursors can further reduce protein adsorption by introducing steric repulsion effects.

Resume : This paper investigates the response of screen printed electrodes (SPEs) based on metallo-porphyrine (Zn, Co and Mn) to biogenic amines (putresceine, cadaverine, histamine etc) extracted from commercial meat samples. The sensitive layer (metallo-porphyrine) was dropcast on the working carbon electrode. Modification of the working electrode with metallo-porphyrine changed the sensing characteristics increasing the oxidation potential for biogenic amines, detecting concentrations down to 0.5 ppm. The SPE have been characterized by AFM spectroscopy and cyclic voltammetry. The modified electrodes presented selectivity towards histamine and were less sensitive towards putresceine and cadaverine. This behavior opens the posibilities for applications both in food safety and medicine.

Resume : Commonly carbon aerogel is synthesized via sol-gel method in monolith shapes from resorcinol and formaldehyde polymerization in the presence of an acid or basic catalyst. They are brittle compacts with high surface area (500-800 m2/g), porosity (40 – 80 %), low mass densities (0.1-0.6 g/cm3). This study report a new route of the sol-gel process performed in centrifugal field. The carbon aerogel yield improved properties related to density, porosity, mechanical strength and microporous structure. The polycondensation reaction and gelification are performed at different G- force (30-150 g). The pyrolysis and thermal treatment carried at 800 and 1300 °C led to carbon aerogel in cylindrical shapes with high mechanical strength, density up to 0.6-0.7 g/cm3, specific surface area around of 800m2/g. The electrochemical properties are dependent on the centrifugation and are comparative with carbon paper. Our results demonstrate the correlation between the primary parameters of the centrifugation process (e.g. G-force) and the physical properties (density, pore structure and specific surface area) of the synthesized aerogel. This allows us to control the gel properties in applications of interest: gas diffusion layers in fuel cells, hydrogen adsorption materials, and electrodes in electrochemical energy conversion.

Resume : In this study, we investigated a new type of 2D crystals – spirographene. A 3D analogue for spirographene is the glitter, predicted in 1994. The topological structure of glitter has been analyzed in several articles. In order to clarify the proprieties we analyzed the structures with reduced dimensions like zero-dimensions effective quantum dots. We proved the most important properties of spirographene and graphene quantum dots: BandGap value, fast excitation energy and its Raman and IR characteristic spectra. With those size dependent characteristics, we further compared these results to graphene and spirographene to obtain the limit of transition from a quantum structure to bulk and calculate the maximum dimensions for a quantum dot. This phenomenon is possible due to the total delocalization of electrons. These results could help steer the new finds towards implementation in technology (energy conversion, storage) and discover new forms of nano-carbon, like spiro-nano-tubes, spiro-nano-corns, etc. Keywords: nano-carbon, spirographene, quantum dots

Resume : The electrical discharge in carbon containing liquids could be a new approach in synthesis of carbon nanoparticles. DC-electrical discharge was carried between two graphite electrodes in: benzene; benzene/toluene, naphthalene in benzene/toluene, decohidronaphthalene, phenol/ decahidronaphthalene and naphthalene/ xilene. During discharge different types of nanocarbon species were obtained and analyzed by SEM/TEM, UV-Vis spectrophotometry, Raman and FTIR Spectroscopy; and DLS. The average diameter of the nanoparticles was 100±5 nm, with various turbostratic structure.. The electrical discharge in carbon containing liquids can be appropriate method to develop new nanocarbon particles with important applications in supercapacitors, nanocomposites or electronic devices.

Resume : The spirographene is an exotic material with unusual properties. The 3D analogue of spirographene is glitter discovered in 1994 by Hoffman. This 2D-material has strong anisotropy and combine metallic, semimetal and semiconductor properties. These properties make it very attractive for numerously applications specially in electronics. This contribution proposes a route for synthesis spirographene using DC electrical discharge in liquids 0 - 1.5 M phenol in decahidronaphthalene (Cis+Trans) In liquor . after synthesis are identified both graphene and spirographene in very low concentrations and nanocarbon. The resulted nanoparticles were analyzed using Raman and FTIR spectroscopy, DLS, UV-Vis spectrophotometry, XRD and HRTEM.

Resume : Commercially available multi-walled carbon nanotubes (MWCNTs) were functionalized in capacitively coupled radio frequency discharges in Ar/O2 and Ar/cyclopropylamine gas mixtures with the aim to obtain carboxylic (?COOH) and amine (?NH2) functional groups, respectively. The pristine and modified MWCNTs were used for the fabrication of working electrodes of a standard three-electrode electrochemical sensor using spray-coating deposition. The sensors were electrochemically characterized by cyclic voltammetry using ferrocyanide/ferricyanide redox couple and dopamine. Dopamine is one of the most studied compounds with CNTs based sensors due to its electroactivity and biological significance. The electrochemical measurements indicated that the sensors with MWCNTs-based working electrodes were able to detect 2.5 mM solutions of both the studied analytes with a good electrochemical response. The electrocatalytic activity of the MWCNTs-based working electrodes towards the electrochemical oxidation of ferrocyanide and dopamine was associated with the MWCNTs functionalization in the following order: carboxyl-containing MWCNT > amine-containing MWCNT > pristine MWCNTs. The values of the oxidation peak currents determined using two samples of modified and one sample of pristine MWCNTs in the solution of 2.5 mM potassium ferrocyanide and potassium ferricyanide in the 0,1M KCl and in the solution of 2.5 mM dopamine in 0.01M HCl were in the range 30 - 54 uA and 86 - 99 uA, respectively.

Resume : High-over-potential for oxygen evolution with chemical stability of boron doped diamond (BDD) electrodes has been expected for various industrial applications such as ozone water purification and effluent water treatment. However, because of its high production cost for BDD electrodes, the industrial scale application has not been widely spread. To reduce the production cost of BDD electrodes and to deposit the BDD thin films on a large area, hot filament chemical vapor deposition (HFCVD) equipment was designed by authors. The high deposition rate of 3 – 5 μm/h, and the large area deposition was succeeded for a none-doped diamond films using CH4, H2 as source gases. In the present study, to achieve the high-rate synthesis of BDD thin films, trimethyl borate (B(OCH3)3) was additionally introduced to this HFCVD system as a dopant. The flow rate of trimethyl borate and the filament-substrate distance, which plays a significant role on the deposition rate and the crystallinity of the films, was precisely adjusted. Based on the scanning electron microscopy (SEM) observation, the X-ray diffraction (XRD) and the Raman spectroscopy analysis, and the cyclic voltammetry (CV) measurement in H2SO4, the crystallinity and the electrochemical performances of the high-rate synthesized BDD films was investigated. As results, the BDD films with a growth rate of higher than 2 m/h was obtained and it showed a wide potential window. The appropriate gas composition and filament-substrate distance under higher rate synthesis of BDD films was discussed in view of the BDD film growth rate and its crystallinity.

Resume : Biomedical applications of nanodiamond (ND) have been investigated extensively due to its low toxicity, non-bleaching fluorescence, and high extensibility of the surface functionality through covalent organic functionalization. For in vivo applications such as drug carrier and imaging probe, ND should form a stable hydrosol under a physiological environment. In this context, we recently found that polyglycerol (PG) functionalization is very effective to impart the sufficient solubility and stability to ND [1]. In addition, the stable hydrogel of PG-functionalized ND (ND-PG) enabled precise characterization of the chemical structure by solution phase NMRs. Quantitative analyses were also conducted by elemental and thermogravimetric analyses. The ND-PG was subjected to further organic transformations at a number of hydroxyl groups on the PG layer to add more functions. As a result, we successfully prepared the ND-based drug carrier with acid-responsive platinum drug [2] and MR imaging probe with gadolinium [3] and applied them to in vivo and in vitro evaluations. [1] L. Zhao, N. Komatsu, Angew. Chem. Int. Ed., 50 (6), 1388-1392 (2011) [2] L. Zhao, N. Komatsu, X. Chen, submitted [3] L. Zhao, N. Komatsu, J. Nanosci. Nanotechnol. in press

Resume : Recent theoretical [1] and experimental [2] studies have suggested that heteroatom-doped carbon nanomaterials such as carbon nanotubes (CNTs) and graphenes as novel materials with exceptional properties for applications including nanoelectronics, energy storage, fuel cells, and electrochemical sensing. However, current synthesis methods of heteroatom-doped carbon nanomaterials usually involve complicated vacuum systems, making it difficult to enable industrial-scale production [1]. Consequently, the development of a controllable synthesis of heteroatom-doped carbon nanomaterials at atmospheric pressure will lead to important advances on both scientific studies and innovation applications. Here we demonstrate an atmospheric-pressure carbonthermic method to produce boron-doped CNTs (BCNTs) and boron-doped graphenes (BGs) with tunable boron atomic concentration ranging from 0.4 to 21.1 atomic percentage (at%). Systematic X-ray diffraction and X-ray photoelectron spectroscopy characterizations indicated that boron atoms were successfully doped into the sp2 graphene lattice of CNTs and graphenes. Detailed high-resolution transmission electron microscopy electron energy loss spectroscopy (HRTEM-EELS) revealed that boron substitution doping mainly occurred on the CNT surface. It is also noteworthy from a practical point of view that the developed atmospheric-pressure synthesis method is amenable to industrial-scale production since it avoids the need for a vacuum system.

Resume : Carbon materials are highly versatile and find numerous applications in areas as diverse as analytical chemistry, energy research and biomaterials. Effective control over carbon interfacial properties is often critical in order to achieve their desired performance in these applications. In this contribution we discuss our progress on the development of structure-activity relationships in amorphous carbons, aimed at understanding the interplay between carbon properties and interfacial charge transfer. We synthesized a range of amorphous carbon thin films via magnetron sputtering and post deposition thermal annealing and characterized them using a combination of spectroscopic and electrochemical methods. We report on quantitative in situ studies of the rate of spontaneous reactions initiated by charge transfer processes using aryldiazonium salts, via nanogravimetry; our results show that the carbon composition can affect both rates and mechanism in these reactions. Also, we report on photoelectron spectroscopy studies of the carbon valence electronic structure and correlate these results to experimentally determined rates of heterogeneous charge transfer at the carbon-solution interface in spontaneous reactions with aryldiazonium salts and in potential driven reactions with outer-sphere redox species. Finally, we discuss the use of Marcus-theory based models for the interpretation of interfacial reactions and charge transfer rates at amorphous carbon surfaces.

Resume : As member of the wide family of carbon materials, the carbon nanotubes (CNTs) offer remarkable properties[1]. These properties are closely related to: i) their nature (narrow size) leading to high specific surface area and ii) their surface chemistry (functionalization abilities) providing tuneable properties for design materials. These features , in combination with their electronic properties are preliminary requirements for sensor material[2]. As a consequence, CNTs are a judicious choice for the development of efficient gas sensors. To be useful and processable in solution, CNTs need first to be chemically or physically modified to overcome their lack of solubility. In this context, non-covalent functionalisation offers the possibility to render the CNTs processable in solution while keeping their electronic properties. More especially, we have developed sensitive material based on CNTs with porphyrins or phthalocyanines as functionnals groups for BTX (benzene, Toluene, Xylenes) detection. Moreover, the dispersions of raw CNTs were also optimized for NO2 and O3 detection. The sensing materials synthesized and characterized by standard techniques (UV-Vis spectroscopy, TGA, TEM, Raman analysis) and sensors response were established by means of resistive and QCM (Quartz Crystal Microbalance) transducers. References: [1] A. Krueger, Carbon Materials and Nanotechnology, Wiley-VCH Verlag, 2010, 123. [2] S. Liu et.al., Coord. Chem. Rev. 254/9-10 (2010) 1101.

Resume : Graphene has great interests because of its incredible electronic and thermal properties for the potential future electronic devices and energy application. However, their intrinsic zero bandgap property and high thermal conductivity are fairly hard to perform the high on-off current ratio of field effect transistor and application to thermoelectric devices. For the overcoming this huddle, graphene nano-strucrues with sub-10 nm scales for the quantum confinement was suggested and showed opening bandgap and high on-off ratio experimentally. However, to achieve a high driving current for the practical device application, densely aligned graphene nano ribbon array should be required. A block copolymer is well-known material for the straightforwardly developing nano-sized pattern from sub-10 nm to 100 nm on large area through the self-assembly. We has investigated highly aligned sub-10 nm pattern formation from polystyrene-block-polydimethylsiloxane (PS-b-PDMS) block copolymer, which is representative for the high block copolymers, and their complex patterns to the application to practical devices. In this presentation, we mainly show sub-10-nm graphene nano-ribbon array field effect transistors which fabricated by cylindrical PS-b-PDMS block copolymer line patterns as a lithographical template on chemical vapor deposition (CVD) grown graphene monolayer sheets. We also briefly introduce graphene nanomesh structures for improving thermoelectric properties.

Resume : We present results of extensive and systematic studies of the mechanical and electronic properties of B- and N-doped graphene(G). The Young’s(Y), bulk(K), and shear(S) moduli and Poisson's ratio(P) have been calculated by means of density functional theory for a representative set of supercells with disordered impurity patterns including aggregates. The structure and related electronic properties of doped G have been investigated on the basis of simulated STM images and differential charge densities presenting sample morphology. Elastic properties are strongly related to the electronic properties of doped systems, especially for heavily doped samples. Local arrangements of dopants, aggregation or separation of impurities play crucial roles in establishing of stiffness in the investigated systems. Interestingly, these findings are different for B- and N-contained samples. We claim that some way of incorporating N in the G layer could even strengthen the doped system in comparison to the pure G. Notably, incorporation of B induces large structural and morphological changes seen in simulated STM images and reduces the stiffness. Y and S increase or decrease with the doping concentration for N or B, respectively, while K and P exhibit opposite trends. We also show how to relate STM measurements with mechanical quality factors in B- and N-doped G, which can be utilized in engineering of graphene-based devices. K.Z.Milowska,M.Woińska,M.Wierzbowska J.Phys.Chem. C117(39),20229(2013)

Resume : We have been developing host-guest methodology for separation of single-walled carbon nanotubes (SWNTs) according to the handedness and diameter with gable-type chiral diporphyrins, designated as diporphyrin nanotweezers, consisting of two porphyrins and rigid spacer in between [1-13]. In this paper, we will talk about next generation of the host molecules focusing on larger diameter of SWNTs, named ?nanocalipers?. [1] X. Peng, N. Komatsu, S. Bhattacharya, T. Shimawaki, S. Aonuma, T. Kimura, A. Osuka, Nature Nanotechnology, 2, 361-365 (2007) [2] G. Liu, F. Wang, S. Chunchaiyakul, Y. Saito, A. K. Bauri, T. Kimura, Y. Kuwahara, and N. Komatsu, J. Am. Chem. Soc., 135, 4805-4814 (2013) [3] G. Liu, A. F. M. M. Rahman, S. Chaunchaiyakul, T. Kimura, Y. Kuwahara, and N. Komatsu, Chem. Eur. J., 19, 16221-16230 (2013) [4] F. Wang, K. Matsuda, A. F. M. M. Rahman, X. Peng, T. Kimura, and N. Komatsu, J. Am. Chem. Soc., 132, 10876-10881 (2010).

Resume : Dimethyl carbonate (DMC) is used as an important building block in fine and bulk chemical industry. It is commonly prepared by phosgenation, oxidative carbonylation, transesterification and urea methanolysis in large-scale production. Our group developed a unique electrochemical system to overcome the problems existed in above well-established methods. To date, the majority of the known homogeneous catalysts for the electro-synthesis of DMC are based on noble metal salts and transition metal N-donor complexes. However, exorbitant cost and poor recycling of the catalysts limited its applications. Our previous study has shown that MOF could be used as heterogeneous catalyst for synthesis of DMC. Based on these investigations, this time we reintroduced a MOF/GO hybrid material used for the electrocatalytic process. The XRD result suggests that the presence of GO did not have any noticeable impact on the formation of the crystalline frameworks. A smaller size of the block structure and more dispersed blocks than MOF alone were observed after the introduction of graphene oxide. No distinct redox peaks were observed before and right after the addition of hybrid electrocatalysts. However, as the reaction proceeded, a couple of nearly reversible redox peaks were obtained from the cyclic voltammograms.

Resume : Biosensors have been extensively developed and applied for biomedical and environmental study. Although there are many different types of biosensing techniques, all these methods require immobilization of biomolecules (DNA, antibody, enzyme) onto the sensor surface. The bio-molecule immobilization step is critical in the development of any sort of biosensor, as it can affect operational properties of the sensor. For many years self-assembled monolayers (SAMs) of alkanethiolates have been widely used for functionalization of the gold surfaces, in spite of low stability of the S-Au linkage at higher temperature or UV radiation. One of the most suitable candidates to substitute SAMs for sensing surface modification is the plasma polymerization providing thin functional films. Among various functional plasma coatings, the amine-rich films are extensively employed for numerous biomedical applications, thanks to the reactivity of the introduced primary amine groups. In this work, cyclopropylamine plasma polymerization is employed to deposit stable amine thin films on the surface of quartz crystal microbalance (QCM) biosensors. The antibody specific to human serum albumin (anti-HSA) is attached to the QCM surface via crosslinkage obtained by intermediate reaction with glutaraldehyde. All steps of the bio-immobilization are controlled by XPS and FT-IR to characterize surface and layer(bulk) chemistry. The stability of the deposited coating during immobilization and within biosensor

Resume : Nanometer size particles having a perfect diamond cubic lattice are fascinating molecules which have recently shown applications that span the fields of organic and inorganic chemistry, physics, materials science, bioengineering, medicine and beyond.[1-­‐3] The term “diamondoid” has been used to name cage hydrocarbon molecules that are totally or mostly superimposable on the diamond lattice; in this context nanodiamonds are unique forms of (C,H)-­‐based nanostructures best described as fully hydrogen-­‐ terminated diamonds of nanometric size. In addition to their perfectly defined chemical formula and structure, diamondoids can be selectively functionalized in determined positions (Scheme 1).[4, 5] We aim to build hybrid materials from multilayer diamondoid/metal deposition: applications in catalysis, optics and electronics are envisaged. In this purpose, several methods of vapor deposition, including physical vapor deposition (PVD), chemical vapor deposition (CVD), and sublimation at atmospheric pressure (APS) are explored. After having determined the vapor pressure curves of several functionalized and native nanodiamonds, we achieved the deposit of 1-­‐hydroxydiamantane (1) by physical vapor deposition (PVD) under strictly anaerobic and low-­‐pressure conditions (1.4x10-­‐6 mBar). The deposits were characterized by XPS and SEM, showing typical hexagonal structures growth. Similarly, other functionalized-­‐diamondoids, such as 4-­‐fluorodiamantane (2), have been deposited under atmospheric pressure, demonstrating that depending on the functions present on the diamond the general structure of the discrete deposits at the micro and nanometer scale can vary dramatically and can be controlled from the deposit conditions. References [1] Schwertfeger, H.; Fokin, A. A.; Schreiner, P. R. Angew. Chem. Int. Ed. 2008, 47, 1022-­‐1036. [2] Kruger, A. Adv. Mater. 2008, 20, 2445. [3] Mochalin, V. N.; Shenderova, O.; Ho, D.; Gogotsi, Y. Nat. Nanotechnol. 2012, 7, 11. [4] Fokina, N. A.; Tkachenko, B. A.; Merz, A.; Serafin, M.; Dahl, J. E. P.; Carlson, R. M. K.; Fokin, A. A; Schreiner, P. R. Eur. J. Org. Chem. 2007, 4738-­‐4745. [5] Schwertfeger, H.; Würtele, C.; Hausmann, H.; Dahl, J. E. P.; Carlson, R. M. K.; Fokin, A. A; Schreiner, P. R. Adv. Synth. Catal. 2009, 351, 1041-­‐1054.

Resume : Tuning the photoluminescence (PL) of carbon nanodots(C-dots) remains a big challenge. In this communication, we demonstrate that the PL of C-dots, as a function of surface-state transitions, can be tuned via changing their size or the extent of surface oxidation. Increasing the size or surface oxidation of C-dots results in reducing the energy gaps of surface states; hence, the large-sized C-dots or the C-dots with high surface-oxidation degree are of long-wavelength fluorescence emissions. Experimentally, this proposed strat-egy can be realized reproducibly by varying the reaction con-ditions, e.g. the reaction time, temperature and concentra-tion of reactants in the preparation of C-dots through oxida-tion of carbon fibers in nitric acid solution. Accordingly, the emissions of fluorescent C-dots have been continuously tuned from 430 nm to 610 nm. This work provides a strategy to intentionally tune the PL properties of C-dots and facili-tates the understanding of their fluorescence mechanism as well.

Resume : Zero dimension graphene quantum dots (GQDs) with smaller lateral dimensions and abundant periphery carboxylic groups exhibits unique fluorescence properties, good biocompatibility and much reactive sites for functionalization, thus providing a great promising applications in gene delivery and cell imaging. Here, a simple and multiple functional nanocarrier of polyethylene glycol(PEG)/poly(L-lactide) (PLLA)-grafted GQDs was proposed. The functionalization of GODs with PEG/PLLA imparts the nanocomposite excellent biocompatibility and superb transfection efficiency of gene probe for micorRNA (miRNA) detection, while the fluorescence of GQDs provides an effective pathway for live cell imaging. Furthermore, simultaneous loading of multiple gene probes on the large specific surface area via π–π stacking and hydrophobic interactions is investigated. Compared to loading with single gene probe, remarkably higher anti-cancer activity was observed from the combined loading. Considering the good biocompabilty, high tranfection efficiency, intrinsic optical properties and large specific surface area for combined loading, the proposed NGO-based nanocarrier is a promising material and may find widespread biological and medical applications.

Resume : The revealing carbon and silicon nanoparticles discovered wide possibilities to use them as hydrogen gas accumulators in energy industry and transportation. The main problem of the storage and safe transportation of the hydrogen gas in industry can be resolved by using carbon and silicon nanotubes which adsorbs the hydrogen gas inside the tube. One of the problems in hydrogen storage in nanomaterials is the hydrogen reverse extraction from nanopores and nanotubes. Extraction of the hydrogen from the nanomaterial can be produced by heating or another effect. However, despite of researchs in this area, the state of hydrogen inside the nanotubes and the effect on the physical properties of the tubes have so far not been studied in detail. In this work the position of hydrogen atoms and molecules in carbon and silicon nanoparticles of different sizes and configurations, as well as its impact on the nanoparticle’s spatial and electronic structure were researched by quantum chemical methods as HF, DFT, MD and DTBM. Also, the nature of π-electron delocalization in various nanostructures of carbon and silicon clusters as clusters, fullerenes, nanotubes and graphene was studied.