Symposium : K
Surface modifications of carbon-related materials II
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| Nanodiamonds for bioapplications : Anke Krueger | ||
| 08:30 | Nanodiamond Platforms for Multi-Functional Therapeutic Agent Delivery Authors : Dean Ho Affiliations : Departments of Biomedical and Mechanical Engineering and Robert H. Lurie Comprehensive Cancer Center, Northwestern University Resume : The faceted architecture of nanoparticulate diamond (ND) surfaces is capable of mediating a broad spectrum of clinically-relevant improvements to drug delivery such as enhanced cancer treatment efficacy and safety. In particular, ND surfaces can prevent early anthracycline elution, resulting in markedly decreased side effects in vivo, while gradually sustained elution and increased retention results in increased therapeutic efficiency. NDs can also be functionalized with a broad array of therapeutics such as small molecules, proteins, antibodies, and DNA/siRNA for applications in cancer treatment, cardiovascular medicine, wound healing, and beyond. In addition, NDs possess uniform dimensions (~2-8 nm in diameter per particle) and material stability that are coupled with observed biocompatibility in vitro and in vivo. Furthermore, NDs can be scalably purified and functionalized for high yield processing. Functional groups are also conducive towards facile, application-dependent molecular linking/conjugation onto the diamond surface for integrative targeting, imaging, and therapy. Our early studies have confirmed robust drug binding to NDs through transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) coupled with in vitro tracking of cellular internalization and quantitative demonstration of favorable cell response through quantitative real time polymerase chain reaction (RT-PCR) assays of inflammatory and apoptosis-regulating gene expression programs. Towards the broadening of ND applicability in clinically-significant treatment scenarios, recent work pertaining to the in vivo validation of ND-based treatment of drug-resistant tumors, synthesis of multi-modal targeted ND complexes, as well as localized wound healing and adhesion suppression using implantable therapeutic release devices will be discussed. | 5 1 |
| 09:00 | Fluorescent nanodiamonds as vector for siRNA delivery to Ewing sarcoma cells Authors : A. Alhaddad1, M.-P. Adam2, C. Durieu3, J. Botsoa2, G. Dantelle4 , S. Perruchas4, T. Gacoin4, C. Mansuy5, S. Lavielle5, C. Malvy1, E. Le Cam3, J.-R. Bertrand1, and F. Treussart2 Affiliations : 1: Laboratoire de Vectorologie et Th?peutiques anticanc?uses, CNRS UMR8203, Universit?aris Sud 11, Institut Gustave Roussy, Villejuif, France 2: Laboratoire de Photonique Quantique et Mol?laire, CNRS UMR8537, ENS Cachan, Cachan, France 3: Laboratoire de Signalisation, noyaux et innovations en canc?logie, CNRS UMR8126, Universit?aris Sud 11, Institut Gustave Roussy, Villejuif, France 4: Laboratoire de Physique de la Mati? Condens? CNRS UMR7643, Ecole Polytechnique, Palaiseau, France 5: Laboratoire des Biomol?les, CNRS UMR7203, ENS, Universit?ierre et Marie Curie, Paris, France. Resume : Diamond nanocrystals (nanodiamond, size <50 nm) have emerged as promising tools to improve drug delivery, with the unique property of containing perfectly stable fluorescent emitters.
We have investigated the ability of nanodiamonds (NDs) to deliver small interfering RNA (siRNA) into Ewing sarcoma cells. Ewing sarcoma is a genetic disease considered as the most frequent bone cancer in children expressing in 85% of cases the oncogene junction EWS-Fli1. siRNA is adsorbed by electrostatic interaction onto the NDs after their coating with PolyEthyleneImide (PEI) cationic polymers.
Using siRNA against EWS-Fli1 oncogene, vectorized by ND-PEI, we obtained a strong inhibition of the gene expression at the mRNA and protein levels compared to usual transfection agent with a lower toxicity. siRNA:ND-PEI treatment is also able to restore the apoptotic behavior of the cells. Moreover, we took advantage of tND intrinsic fluorescence to monitor the release kinetics of fluorescently-labeled siRNA from their carrier, in the cytosol [A. Alhaddad et al., Small 7, 3087-3095 (2011)].
Finally, we investigated the internalization pathway of siRNA vectorized by two different cationic NDs, using Transmission Electron and fluorescence microscopies. Poly(allylamine) Hydrochloride (PAH)-coated NDs follow a clathrin-mediated endocytotic pathway accompanied by a slow release of siRNA, while PEI-coated NDs are internalized by macropynocitosis, a process allowing for the release of siRNA in the cytosol. | 5 2 |
| 09:15 | Detection and targeting of fluorescent ND in biological samples Authors : Richter J., Petrakova V., Cigler P., Ledvina M., Nesladek M., Kreuger A., Fiserova A. Affiliations : Institute of Microbiology, Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic; Czech Technical University in Prague, Faculty of Biomedical Engineering, Kladno, Czech Republic Institute of Physics, Academy of Sciences of the Czech Republic, v.v.i, Prague, Czech Republic; Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic; Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic; IMOMEC division, IMEC, Institute for Materials Research, University Hasselt, Diepenbeek, Belgium; Institut f?rganische Chemie, Julius-Maximilians-Universit?W?urg, W?urg, Germany; Institute of Microbiology, Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic Resume : The aim of our study was to optimize techniques for detection of fluorescent nanodiamonds (FND) in live cell samples for further use in the monitoring of cancer processes. In our experiments, we used HPHT fluorescent nanodiamonds of 2 sizes (35nm and 100nm). By confocal microscopic spectral measurement, we detected NV0 and NV– emission spectra and optimized the microscope setup (excitation wavelength, emission window, detector settings etc.) for their detection (either pure FND or within living cells). FND uptake capabilities were tested in vitro in IC21 macrophage cell line, in human peripheral blood mononuclear cells and ex vivo in mouse peritoneal macrophages. The particles were found in the cytoplasm – i.e. not entering the cell nucleus.
Spontaneous uptake by HT29 human adenocarcinoma cell line was found to be significantly weaker than in the phagocytic cell types. Bombesin-covered FNDs were tested for possible targeting to gastrin related peptide receptor (GRPR) expressed on adenocarcinomas. We found out that bombesin increased the particle uptake slightly compared to plain FND. However, effective targeting to cancer cells still requires further optimization of both FNDs size and/or targeting molecules.
As immunological evaluation of FND impact on cells requires staining of various surface antigens and their detection, we analyzed the detectability of FND-containing cells by flow cytometry and possible combination with conventionally used fluorochromes. In our BD LSRII flow cytometer setup with 4 excitation wavelengths (405nm, 488nm, 561nm and 633nm) covering all commonly used fluorochromes, we detected FNDs fluorescence in 11 of 17 emission channels leaving 6 channels (mainly in 405nm excitation set) to be used for other fluorochromes.
Our research proved the possibility of FND detection by conventional fluorescence-based techniques used in biological research opening the possibility for further utilization of such carriers for monitoring of processes within living cells.
Supported by European R&D project 245 122 FP7 – DINAMO | 5 3 |
| 09:30 | Targeted Nanodiamond-Lipid Hybrids Enhance Cancer Imaging and Therapy Authors : Laura K Moore, Edward K Chow, Eiji Osawa, Dean Ho Affiliations : Northwestern University, Evanston, IL; University of California San Francisco, San Francisco, CA; NanoCarbon Research Institute, Shinshu University, Ueda, Nagano, Japan; Northwestern University, Evanston, IL, Robert H. Lurie Comprehensive Cancer Center, Chicago, IL Resume : Diamond nanoparticles (NDs) have been shown to be highly biocompatible vehicles for the delivery of therapeutic and imaging agents. By promoting internalization and retention of their cargo while limiting non-specific uptake during circulation NDs are able to increase the efficacy and reduce the toxicity of a number chemotherapeutic agents, such as doxorubicin and paclitaxel. In order to target cancer cells for imaging and therapy, we have developed a self-assembled nanodiamond-lipid hybrid particle (NDLP) that preserves the potent interactions between ND surfaces and drug or fluorophore. We report the synthesis, characterization and evaluation of epidermal growth factor receptor (EGFR) targeted NDLPs carrying either a fluorophore or anthracycline therapeutic, for targeted imaging or therapy of breast cancer. Targeted delivery of NDLPs carrying a near-infrared fluorophore resulted in increased fluorescence retention in EGFR overexpressing breast cancer cells (MDA-MB-231) both in vitro and in vivo, as compared to cells not-overexpressing the receptor (MCF7). Systemic delivery of anti-EGFR targeted NDLP-chemotherapeutic prevented drug lethality and resulted in tumor regression in mouse breast cancer xenografts (MDA-MB-231 cells). Here we demonstrate NDLP-mediated targeted imaging and therapy of breast cancer, however because the system is highly modular it could be readily modified to target any number of cancers or other human diseases. | 5 2 |
| 09:45 | Photoluminescent Oxidized Carbon Nanostructures Authors : O. Shenderova1, S.Hens1, S.Turner2, I.Vlasov3 Affiliations : 1International Technology Center, Raleigh, USA; 2EMAT, University of Antwerp, Antwerp, Belgium; 3General Physics Institute, Moscow, Russia Resume : Bright, nontoxic, photoluminescent nanoparticles are needed for bioimaging and biomedical diagnostics. The photoluminescent nanoparticles of nanodiamonds and carbon dots are alternatives to cytotoxic quantum dots and metallic nanoparticles. Fluorescent nanodiamonds have been prepared by a variety of research groups by high energy bombardment to produce photoluminescence emission colors of red and green wavelength. While, carbon dots are formed by graphite oxidation and have a photoluminescence emission that spans the visible range. We demonstrate that other photoluminescent (PL) nanostructures, namely carbon-dots decorated nanodiamonds may be formed by oxidation of detonation soot and nanoplatelets\nanoribbons may be formed by oxidation of graphitic carbon using common acids. The treatment of micrographite, nanographite, and highly oriented pyrolytic graphite, and onion-like-carbon with acids produced colloidal supernatant solutions that photoluminesce across the visible wavelength range. These suspensions exhibit a blue-shift with either increasing reaction time or temperature. Gel electrophoresis was used for separation of species with different PL emission, from blue to red. Details in morphology of different PL oxidized nanocarbons based on transmission electron microscopy will be reported . | 5 5 |
| 10:00 | coffee break | |
| Diamond surfaces for biosensors : Bohuslav Rezek | ||
| 10:30 | New route of diamond derivatization for biosensors fabrication Authors : C. Agnès(a,b,c), S. Ruffinatto(a,b), A. Bongrain(c), J.C. Arnault(c), F. Omnès(a), P. Mailley(b), P. Bergonzo(c) Affiliations : (a) CNRS-Institut Néel, Av. des Martyrs, BP166, 38042 Grenoble Cedex 9, France (b) CEA, INAC, SPrAM, CEA-Grenoble, F-38054 Grenoble, France (c) CEA, LIST, Diamond Sensors Laboratory, F-91191 Gif-sur-Yvette, France Resume : Bioelectronic relates on the design of functional devices enabling accurate and sensitive interfacing of biological entities including complex living bodies as well as extracted biomolecules. More particularly, biosensors and biochips represent a specific class of devices in which biomolecules, such as oligonucleotides, antibodies or enzymes, are intimately associated to a functional substrate that translates their working function (recognition, metabolism…) into a readable signal.
In such a context, diamond is recognized as promising transducer material since it provides a wide range of useful properties including extensive chemical stability and corrosion resistance, mechanical hardness and rigidity, thermal conductance and superior electrochemical properties such as low background current, wide potential window when diamond is heavily doped with boron.
Associated to its carbon nature enabling covalent surface functionalization, boron doped diamond (BDD) is a material of choice for electroanalysis and for interfacing with (bio-) molecular entities. Usual approach for diamond functionalization are based on alkenes photochemistry [1] and diazonium salts [2,3]. However, these methodologies follow long and complex multistep strategies.
We have recently developed a novel one-step derivatization strategy that is fast (less than 2 minutes), selective, leading to a monolayer covalently linked to the surface, and compatible with patterning approaches.
In the framework of this presentation, this new functionalization strategy will be presented.
Different (bio-) molecules were immobilized on diamond surfaces and characterized using fluorescence spectroscopy, electrochemistry, FTIR and XPS. Their stability and bioactivity was demonstrated using the avidin-biotin couple. This opens up the route for the fabrication of biosensors, where the transduction can be based on cantilever approaches. For example, single strained DNA and antibodies can be immobilized using our approach on sensors and applied to demonstrate the selectivity and the ability of this new method for DNA and cell recognition. In parallel, redox enzymes were also immobilized enabling the fabrication of second- and third-generation amperometric enzymatic biosensors.
[1]Yang et al, Nature Mat., 1 (2002) 253
[2] Rezek et al, J. Am. Chem. Soc., 128 (2006) 3884
[3] Lud et al, J. Am. Chem. Soc., 128 (2006) 16884 | 6 1 |
| 11:00 | Electrochemical adjustments of the diamond surface chemistry for optimized protein interaction Authors : René Hoffmann, Nianjun Yang, Christoph E. Nebel Affiliations : Fraunhofer-Institute for Applied Solid State Physics (IAF), Freiburg 79108, Germany, rene.hoffmann@iaf.fraunhofer.de Resume : In biotechnological applications that rely on a protein-electrode interface, enzymatic biofuel cells being an important example, the ideal electrode surface would resemble the properties of a protein surface. In this case, no reconciling intermediate layers (which can limit electron transfer rates) would be required. The properties of a protein surface are defined by the chemistry of sp3 hybridized carbon. In this contribution it will be shown that if the sp3 carbon chemistry is electrochemically modified, the diamond surface can be adjusted to a “solid protein(-mimicking) surface”.
Important ingredients for such a surface are, in an adjustable mixture, hydrophobic surface properties (C-H termination), and a hydrophilic character (C-OX). By electrochemical treatments at high voltages (-35 V to +10 V), the hydrophilic-hydrophobic character of the diamond surface can be gradually and precisely adjusted to achieve ideal activity of proteins bound to the electrode. The model protein cytochrome c exhibits high activity on a surface that is covered by 70-80% with oxygen moieties. It will also be presented, if this concept is also applicable for laccase, a protein which is highly relevant for biofuel cells due to its catalytic activity for oxygen reduction. The structure and activity of the two proteins on the solid diamond surface will be compared with respect to their specific biophysical properties. | 6 2 |
| 11:15 | Dendritic Gold Hierarchical architecture on boron-doped diamond surface: tailoring growth, properties and biosensor applications Authors : Meichuan Liu, Guohua Zhao*, Lu Zhuang, Kang Chen Affiliations : Department of Chemistry, Tongji University, Shanghai 200092, PR China Resume : The hierarchical nanostructures built from nanounits, which exhibit unique physical and chemical properties different from those of nanounits, have been a challenging scientific topic and widely investigated. In this work, a dendritic gold hierarchical architecture was constructed on boron-doped diamond (BDD) hybrid film surface by a controllable double template path and an electroless solution deposition process. The tailoring growth of gold nanodendritites was characterized and revealed by scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The potential growth mechanism of the hierarchical structure was proposed. The enhanced electrochemical behaviors of the dendritic Au/BDD, resulting from the large surface area and hierarchical structure of the dendritic Au and the particular electrochemical properties of BDD, were evaluated. The dendritic Au/BDD further illustrated promising applications in biosensor construction and environmental analysis.
(Acknowledgements: This work is supported by the National Natural Science Foundations of China (NSFC) (Nos. 21077077, 21107081), NSFC Research Fund for International Young Scientists (Nos. 21050110116, 21150110336) and the Fundamental Research Funds for the Central Universities.) | 6 3 |
| 11:30 | Catalytic formation of nanometer scale holes in diamond for sensor applications Authors : Hasan-al MEHEDI*, C. Hebert, S. Ruffinatto, E. Gheeraert and F. Omnes Affiliations : Institut Néel, CNRS and Université Joseph Fourier 25 avenue des Martyrs, BP166, 38042 GRENOBLE Cedex 9 Resume : Formation of nanometer scale holes in diamond has attracted much interest in recent time because of its promising contribution in nanostructuration of diamond based devices. However, in the case of sensors such as those based on nanopores in a membrane, regular etching technique, lithography and reactive ion etching, fails to create narrow (10 to 50 nm in diameter) and long (typically longer than 300 nm) holes in the membrane. We have developed a fast, cost effective and simple etching method of diamond based on the catalytic reaction of metallic nanoparticles on carbon in a hydrogen atmosphere. In this process, each metallic nanoparticle located on the diamond surface dissolves the underneath carbon. The dissolved carbon is desorbed in the form of methane from the metal surface making the nanoparticle to enter the diamond sample. Experiments were carried out in hot-filament assisted CVD diamond growth chamber. Different types of diamond (polycrystalline, nanocrystalline and 100-oriented monocrystalline diamond) and transitions metals (Ni, Pd, Co, Pt and Fe) were used as substrate and catalyst respectively. With this technique we were able to produce square shaped etch pits (10x10 to 100x100 nm2) with a length of hundreds of nm. By using patterned metal films on 100-oriented monocrystalline diamond we also managed to create inverse-pyramidal shaped etched holes (100x100 to 1500x1500 nm2), revealing {111} atomic planes, as deep as 300-700 nm. As a first application, multiwalled carbon nanotube forests were grown inside the holes, using embedded nanoparticles as catalyst, resulting in a strong mechanical binding between nanotubes and diamond. This approach could be very attractive for in vivo applications where dispersion of CNTs should be avoided. | 6 4 |
| 11:45 | Tip Modification of Boron-Doped Diamond Nanowires with Ni Nanoparticles for Three-Dimensional Catalytic Reactions Authors : Nianjun Yang,* Waldemar Smirnov, Ren?offmann, Jakob Hees, Christoph E. Nebel Affiliations : Fraunhofer-Institute for Applied Solid State Physics (IAF), Freiburg 79108, Germany Resume : Surface modifications of diamond with metal catalysts are important for a variety of chemical catalytic reactions, for example to split CO2 etc. Boron-doped diamond is a good electrode material for electrocatalytic reactions because i) a strong metal-diamond electrode interaction can be achieved due to the metal-carbide formation, ii) the contribution of background current of boron-doped electrode is negligible in the potential region of interest, iii) the catalysts can be readily deposited using different techniques, iv) the boron-doped electrodes are stable and inert in various harsh conditions.
We will introduce three-dimensional electrocatalytic reactions using tip functionalized boron-doped diamond nanowires as the electrode. The nanowires with the length of up to 1 µm, the diameter of 20-30 nm, and the density of 1010/cm2 were produced using a top-down approach and self-organized Ni nanoparticles (NPs) as etching mask. SEM images show the tips of diamond nanowires (NWs) were modified with thermally formed Ni NPs, which behavior as the catalyst. The cyclic voltammograms of Ni-NPs-NWs in a 1.0 M NaOH solution show a reduction wave at 0.47 V (vs. Ag/AgCl) and an oxidation wave at 0.58 V. The oxidation currents of glucose, methanol, and ethanol on the Ni-NPs-NWs were 2-10 times higher than those on Ni nanoparticles coated flat diamond electrodes, and 10-30 times higher than those on bare diamond electrodes. The results will be also compared with those shown in literature. | 6 5 |
| 12:15 | Lunch time | |
| Graphene and CNTs: bioapplications : José Garrido | ||
| 13:45 | Graphene-based biosensing and antibacterial applications Authors : Chunhai Fan, Wenbin Hu, Qing Huang Affiliations : Shanghai Institute of Applied Physics, Chinese Academy of Sciences Resume : Graphene is a monolayer of tightly packed carbon atoms that possesses many interesting properties and has numerous exciting applications. Coupling nanomaterials with biomolecular recognition events represents a new direction in nanotechnology toward the development of novel molecular diagnostic tools. We herein report a graphene oxide (GO)-based multicolor fluorescent DNA nanoprobe that allows rapid, sensitive, and selective detection of DNA targets in homogeneous solution by exploiting interactions between GO and DNA molecules. Because of the extraordinarily high quenching efficiency of GO, the fluorescent ssDNA probe exhibits minimal background fluorescence, while strong emission is observed when it forms a double helix with the specific targets, leading to a high signal-to-background ratio. We also find the antibacterial activity of two water-dispersible graphene derivatives, graphene oxide (GO) and reduced graphene oxide (rGO) nanosheets. Such graphene-based nanomaterials can effectively inhibit the growth of E. coli bacteria while showing minimal cytotoxicity. Macroscopic freestanding GO and rGO paper can be conveniently fabricated from their suspension via simple vacuum filtration. Given the superior antibacterial effect of GO and the fact that GO can be mass-produced and easily processed to make freestanding and flexible paper with low cost, we expect this new carbon nanomaterial may find important environmental and clinical applications. | 7 1 |
| 14:15 | Functionalized graphene oxide as selective regulators of protease, serum factors, gene expression, and microbial growth Authors : Liling Jin, Xiaofang Tan, Jing Zhang, Kai Yao, Jia Tang, Kai Yang, Shuai Zhang, Zhuang Liu, Rui Peng Affiliations : Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou, Jiangsu, P. R. China Resume : Graphene oxide (GO), a member of the SP2 carbon nanomaterials family, has drawn huge attention in the past a few years, especially its great potential in biological fields, such as biosensors, molecular imaging, drug delivery, and in vivo therapy. As more and more biomedical applications of GO been explored, critical issues as the biosafety and biological effects of GO arise and must be addressed before any further massive applications. My group is currently working on the biological effects of GO functionalized with polyethylene glycol (PEG). By varying the preparation methods, the coating polymers, or replacing surface functional groups, a series of PEGylated GO were prepared. Although no obvious cellular toxicity has been observed, these PEGylated GOs exhibit distinct, yet interesting properties and effects when interacting with biological organisms or molecules, ranging from bioactive small molecules (e.g. enzyme inhibitors), proteins (enzymes, nuclear factors, serum proteins, etc.), and microorganisms (bacteria and fungi). Our results demonstrate that such interactions can be regulated through and are closely associated with their surface/interface chemistry. Furthermore, one type of PEGylated GO in particular, has been shown to act as selective regulators of protease activity and thermostability, cellular gene expression, serum complement levels, as well as growth of microbes, suggesting promising applications and potentials of functionalized GO in enzyme engineering, biosensing, fermentation engineering, and biomedical engineering. | 7 2 |
| 14:30 | Nano-graphene for Cancer Theranostics Authors : Kai Yang, Liangzhu Feng, Zhuang Liu* Affiliations : Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, China. E-mail: zliu@suda.edu.cn Resume : Owing to its interesting physical and chemical properties, graphene has shown promise in a wide range of fields including biomedicine. In the past few years, our group has explored the applications of graphene for potential cancer therapies and imaging. It was shown that functionalized nano-graphene could be used as effective multi-functional nano-carriers for the intracellular delivery of drugs, photosentizers and genes. Excellent in vivo cancer treatment efficacy in mouse tumor models was achieved by the graphene-based photothermal therapy. Nano-graphene coupled with other inorganic nanoparticles could further serve as a multi-funcitonal probe for imaging-guided cancer therapies. In the mean time, using a radiolabelling method, we found that PEGylated graphene could be excreted from mice by feces and urine, without rendering noticable toxicity to the treated animals. Our results collectively encourage the further exploration of graphene-based cancer theranostics.
References
1, Biomaterials, DOI:10.1016/j.biomaterials.2011.11.064
2, ACS Nano, 5, 7000-7009 (2011)
3, Materials Today, 14, 316-323 (2011)
4, Nanomedicine, 6, 317-324 (2011)
5, ACS Nano, 5, 516-522 (2011)
6, Nano Lett. 10, 3318–3323 (2010) | 7 3 |
| 14:45 | Synthesis of switchable near infrared absorbing boron azadipyrromethene single-wall carbon nanotube conjugates Authors : Silvia Giordani, Kevin Flavin, Ilona Kopf, Julie Murtagh, Marco Grossi, Donal F. O’Shea Affiliations : Trinity College Dublin, University College Dublin Resume : Carbon nanotubes display unique structures and remarkable physical properties. They have nanoscale dimensions, and can be modified through covalent bonding of functional organic molecules, opening the way to structural materials of high technological importance. (1)
We have developed a novel protocol for preparing high purity oxidised SWNTs that preserve optical properties. (2) We have synthesised novel red/near infrared (NIR) absorbing boron azadipyrromethene single-wall carbon nanotube conjugates and demonstrated the ability to reversibly switch on and off the fluorescence by modulation of pH. (3)
References:
(1). Singh P., Campidelli S., Giordani S., Bonifazi D., Bianco A. and Prato M. Chem. Soc. Rev. 2009, 38, 2214- 2230.
(2). Flavin K., Kopf I., Del Canto E., Navio C., Bittencourt C. and Giordani S. J. Mat. Chem. 2011, 21, 17881 – 17887.
(3). (a) Flavin K., Lawrence K., Bartelmess J., Tasior M., Navio C., Bittencourt C., O’Shea D., Guldi D.M. and Giordani S. ACS Nano 2011, 5, 1198–1206. (b) Flavin K., Kopf I., Murtagh J., Grossi M., O’Shea D. and Giordani S., Supramol. Chem. 2011, in press. | 7 4 |
| 15:00 | Strong adhesive carbon nanotube coating on diamond electrode for highly sensitive boisensing Authors : Clement Hebert, Sebastien Ruffinatto, Michel Mermoux, David Eon, Pascal Mailley, Franck Omnes Affiliations : Institut Neel CNRS et Universite Joseph Fourier BP 166 F-38042 Grenoble Cedex 9 France, CEA/INAC/SPrAM/CREAB 17 rue des Martyrs 38054 Grenoble Cedex 9 Resume : Carbon nanotube (CNT) is thought to be one of the best electrode coatings for neural interfacing. Many teams proved a dramatic improvement of the neural signals and even the neural growth on CNT forest. However recent studied highlighted that dispersed CNTs could be harmful because they cannot be eliminated by macrophages or they can enter in the cell nucleus leading in both case to cancers. This prevents the use of the fantastic features of CNTs for in-vivo application. Fortunately some survey stressed that CNTs anchored to the electrode would be harmless. In this study we present a new way to tackle this issue by embedding CNTs inside diamond.
Boron Doped Nanocrystalline diamond was nucleated with the bias enhanced nucleation method in a SEKI Microwave Plasma CVD reactor and grown in a NIRIM type. The samples were then drilled thanks to a catalytic etching enhanced by hot filament performed with nickel and palladium nanoparticles. Those metallic particles were recycled as catalysts for the growth of dense mutiwalled CNT forests afterwards.
AFM and electrochemical comparative studies between CNT grown on diamond and inside diamond were performed showing an improvement of both the mechanical and electrical connectivity in the case of embedded CNTs.
Thanks to the high active surface area of CNTs, a very sensitive HorseRadish Peroxydase biosensor was successfully developed. A direct electrical coupling of the enzyme to the carbon nanotubes was demonstrated. | 7 5 |
| 15:15 | Coffee break | |
| Sensing applications of nanodiamonds : Dean Ho | ||
| 15:45 | Redox Reactions at Nanodiamond Surfaces Authors : Katherine B. Holt, Jan Scholz, A. James McQuillan Affiliations : Department of Chemistry, University College London; Department of Chemistry, University of Otago, New Zealand Resume : Nanodiamond (ND) is formed by detonation of carbon-based explosives and consists of individual diamond nanoparticles of ~ 5 nm in diameter. This material is attracting much interest at present in possible biomedical applications such as drug delivery, intracellular imaging and biosensing. Our interest lies in its unexpected redox properties [1,2] as we find that when immobilized on an electrode it is able to undergo direct oxidation and reduction and can also undergo electron transfer with solution redox molecules such as IrCl62-. As undoped diamond is an insulating material, with a band gap of 5.5 eV we have suggested that this redox activity must be associated with its surface. By necessity bonding at the surface is unsaturated and due to the acid treatment used in purification highly oxidized. The ND surface contains an array of different surface functionalities, such as carboxylic acid, alcohols, quinones and ketones etc. As these groups can undergo redox transformations they may be responsible for the observed redox activity.
This talk will discuss recent experiments to elucidate the mechanisms behind electron transfer at the ND surface. This study uses Attenuated Total Reflectance InfraRed (ATR IR) spectroscopy to monitor changes in the vibrational frequencies of the surface functional groups of the ND in the presence of redox probes. In ATR IR the IR beam is directed through an internal reflection element (IRE), on top of which a thin layer of the nanomaterial is immobilised. The IR beam is reflected internally at the surface of the IRE, but the beam also penetrates the immediate environment above the prism surface as an evanescent wave. An IR vibration spectrum of the material within range of the evanescent wave can therefore be obtained and as only a thin layer is probed, solvent absorption is minimised. Use of nanomaterials ensures that a high surface area is available to be probed, allowing good quality IR spectra of the redox-active surface functional groups to be obtained.
[1] Electrochemistry of Undoped Diamond Nanoparticles: Accessing Surface Redox States, K. B. Holt, E. Millan-Barrios, D. J. Caruana, J. Am. Chem. Soc., (2009) 131, 13272+.
[2] Undoped diamond nanoparticles: origins of surface redox chemistry, K. B. Holt, Phys. Chem. Chem. Phys., (2010) 12, 2048 | 8 1 |
| 16:15 | Functionalized diamond nanoparticles as sensitive layers for gas sensing and recognition in a multichannel SAW sensor system Authors : A. Trouvé, B. Tard, H. A. Girard, E. Scorsone, P. Bergonzo Affiliations : CEA, LIST, Diamond Sensors Laboratory, F-91191 Gif-sur-Yvette, France Resume : Diamond nanoparticles (NDs) have received considerable interest over the last decade owing to their great promises for biomedical, composite, optic and technological applications due to their outstanding properties. Here we have used ND coated SAW (Surface Acoustic Wave) devices in a multichannel apparatus for gas detection. The system has been successfully used for explosive (eg. TNT) as well as warfare agent detection (eg. sarin, mustard). Various functionalizations of NDs enable to provide the sought partial selectivity required for detection. In fact, the sp3 surface carbon offers a wide range of possibilities to graft specific chemical receptors through covalent binding onto their surface using standard wet chemistry or plasma treatments.
Here, we will focus on the NDs functionalization chemistry. When compared with typical polymeric approaches, NDs can be used as a versatile platform on which functional groups with a high affinity toward a selected target are grafted, without interfering with the SAW transducer. To increase sensor selectivity, we have study diverse surface terminations obtain by electrostatic attachment or C-C covalent bonding. Hydrophobic (–CF3), hydrophilic (–OH) and acid surface (–COOH) were synthesized and characterized.
The resulting sensors were able to detect gases such as NH3 or H2S, nitroaromatic compounds such as DNT, a marker for explosive TNT, or warfare agents at concentrations in the ppb range with fast response and no memory effect. | 8 2 |
| 16:30 | High density nanodiamond deposit for sensing applications Authors : Schmidlin Loïc(1), Pichot Vincent(1), Josset Sébastien(1), Comet Marc(1), Rabu Pierre(2), Spitzer Denis(1) Affiliations : (1) NS3E « Nanomatériaux pour les Systèmes Sous Sollicitations Extrêmes » UMR CNRS-ISL no 3208, French-German Research Institute of Saint-Louis, 5 rue du général Cassagnou 68301 Saint-Louis, France (2) Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), UMR 7504 CNRS- Université de Strasbourg, 23 rue du Loess, Boîte Postale 43 67034 Strasbourg Cedex 02, France Resume : Electrophoretic deposition is an efficient method to deposit colloidal particles on an electrode by using an electrical field. This technique has already been used for the deposition of nanoparticles or nanodiamonds and was here applied to detonation ultra-nanocrystalline diamonds (D-UNCD). To obtain ultrathin D-UNCD deposit, the use of suspension containing individual nanodiamonds is crucial.
The D-UNCD used in this study were synthesized and purified at the ISL. The D-UNCD particles surface is mainly covered by carboxylic groups resulting in a negative surface charge when suspended in water. A mechanical treatment was applied to the D-UNCD to obtain suspension containing separated nanodiamonds with an average size of 3-5 nm. An electrical field was applied to this colloidal suspension to deposit the D-UNCD on a Highly Oriented Pyrolitic Graphite electrode. The obtained deposits were characterised by Atomic Force Microscopy (AFM). The deposits topography is 5 nm, corresponding to a monolayer deposition of D-UNCD. The deposits density obtained with this technique is estimated to be over 10^12 particles/cm2. Due to the proximity of the nanodiamonds particles, an AFM tip with a radius of 1 nm wasn’t able to discern them. To our knowledge such a density has never been obtained before. Such deposit is suitable for sensing applications. | 8 3 |
| 16:45 | Accurate Determination of Electrokinetic Properties of Nanodiamond Particles Authors : N. Petrova, F. Gareeva, A. Zhukov, A. Vargas, O. Shenderova, A.Koscheev, I. Petrov Affiliations : South Ural State University, 454080, Chelyabinsk, Russia; St. Petersburg State University, 198504, St. Petersburg, Russia; International Technology Center, Raleigh, 27714, USA; Karpov Institute of Physical Chemistry, Moscow, Russia; SKN, Snezinsk, Russia Resume : Electrokinetic properties of nanodiamond (ND) particles are among most important ND characteristics, inherently connected with its surface chemistry and specific to ND processing. Electrokinetic potential (zeta potential), obtained from measured electrophoretic mobilities of ND particles, is often reported by researchers. But are reported values accurate? Typically electrophoretic mobilities measurements are carried out using technique of the laser Doppler electrophoresis. Then, one of two most popular theoretical expressions of electrophoresis are typically used, either Smolukhovski’s or Henry’s, for conversion of mobilities into electrokinetic potential values. However, in order to obtain accurate zeta potential, electrokinetic theories must be correctly used for a given type of nanoparticles and applied within the range of their validity. An important feature of NDs produced by detonation synthesis (DND) is that they form nanoporous aggregates consisting of 4-5nm primary particles. This factor should be taken into account when deriving zeta potential for DND. In the current paper we provide thorough analysis of the conditions of the applicability of different theories of electrophoresis to DND, as well as monolithic nanodiamond particles of static synthesis at different background electrolytes. Recommendations for electrokinetic potential calculations for different types of ND particles will be provided. | 8 4 |
| 17:00 | Nitrogen doping of detonation nanodiamonds Authors : Pichot V.(1), Stephan O.(2), Comet M.(1), Mory J.(1), Fousson E.(1), March K.(2), Spitzer D.(1) Affiliations : (1) NS3E « Nanomatériaux pour les Systèmes Sous Sollicitations Extrêmes » UMR CNRS-ISL no 3208, French-German Research Institute of Saint-Louis, 5 rue du général Cassagnou 68301 Saint-Louis, France (2) Laboratoire de Physique des Solides (UMR CNRS 8502), bât. 510, Université Paris Sud, 91405 Orsay, France Resume : The presence of nitrogen/vacancy centres inside nanodiamond particles is of great importance to confer them luminescent properties which open a wide field of applications in biology and in quantum physics. Recent studies reported an intermittency luminescence in 5 nm detonation nanodiamonds. Varying nitrogen content inside detonation nanodiamonds should be very helpful to obtain stable photoluminescence properties.
Nanodiamonds are synthesized at the ISL by detonation using a high explosive mixture composed of trinitrotoluene (TNT) and hexogen (RDX) (70 / 30). The detonation of the charge leads to a powder containing nanodiamond crystallites (Φ ~ 5 nm). The content of the nitrogen present inside these nanoparticles was determined by Electron Energy-Loss Spectroscopy (EELS) and is about 3 wt %. The doping nitrogen comes from the explosive molecules which contain a lot of nitrogen atoms. A study on the nitrogen doping of detonation nanodiamonds was carried out.
The experimental results demonstrate that the nitrogen content strongly depends on the precursors used in the explosive charge composition. We have demonstrated that with the incorporation of a nitrogen rich compound, it is possible to increase the nitrogen content by a factor two or three. A careful study of the nitrogen spectroscopic signature revealed that it is present inside the nanodiamond core in a sp3 hybridization configuration. Modifications of the luminescent properties of such particles are expected. | 8 5 |
| Poster session : Naoki Komatsu | ||
| 17:15 | Large area rGNO film by electrospinning/electrospray techniques Authors : Yingjun Liu, R. Vasant Kumar Affiliations : Department of Materials Science and Metallurgy, University of Cambridge Resume : Our paper presents a simple, efficient, low-cost and environmentally friendly electrochemical method to produce reduced graphene oxide (rGNO) from exfoliated graphene oxide (eGNO), which is in-depth exfoliation product of graphite oxide (GO). The eGNO precursor is firstly dispersed as a stable colloid in a wide range of pH, and then is deposited on various substrates by a combination of electrospinning/electrospray techniques. By continuously adjusting the pH and applied voltage, the eGNO is successively reduced to large area film of rGNO with different mechanical and electrical properties. The film of rGNO is easily transferred to other substrate for purpose of electrochemical sensors and energy storage. | 9 1 |
| 17:15 | Effect of Heat Treatment of Nanodiamonds on the Scratch Behavior of Polyacrylic/Nanodiamond Nanocomposite Clear Coats Authors : S.A. Sajjadia, S.M. Zebarjad, M.H. Avazkonandeh-GharavolM. Mohammadtaheri, M. Abbasi, and K. Mossaddegh Affiliations : Department of Materials science and Engineering, Ferdowsi University of Mashhad, Mashhad, Iran Resume : Application of carbon nano-family members as reinforcement phase in polymeric matrix has become very common in recent years. To insure good dispersion of nanoparticles in matrix their surface should be modified to become compatible with the special medium in which they are added. In the current paper, effects of heat treatment of nanodiamond particles on the scratch behavior of polyacrylic/diamond nanocomposite coatings were studied. Two types of nanodiamond, i.e. one produced by detonation synthesis (DND) and the other produced by nondetonation synthesis (NDND) were used as reinforcement phase to increase scratch resistance of polyacrylic base polymeric clear coat. Heat treatment was used as the surface modification route. Coatings containing both types of particles in two surface conditions (as-received and heat treated) were compared to each other and also to the neat polyacrylic coating. The results showed strong effect of heat treatment on scratch resistance of coatings based on the scratch width criterion. The effect of heat treatment was more pronounced on DND particles than on NDNDs. However the pendulum hardness showed a reverse trend. | 9 2 |
| 17:15 | The study on surface modification of multi walled carbon nanotubes Authors : S. Sahebian, S. M. Zebarjad, J. Vahdati Khaki Affiliations : Department of materials and metallurgical engineering, School of engineering, Ferdowsi University of Mashhad, P.O. Box 91775-1111, Mashhad, Iran Resume : Acids are commonly used in purification procedures in order to remove catalyst particles from the as-produced material. It was found that desirable modification to MWNTs occurred after acid treatment. In the current research the oxidation behavior of multi-walled carbon nanotubes (MWCNTs) with concentrated nitric acid was studied. To investigate the role of acid treatment on oxidation behavior and functionalization of MWCNTs different techniques such as X-ray diffraction (XRD), transmission electron microscopy (TEM), Thermogravimerty Analyzer (TGA), Fourier transform spectroscopy (FTIR) were performed. The results of Fourier transformed infrared spectroscopy present the formation of oxygen containing groups such as C=O and COOH after modification by concentrated nitric acid. It means that carboxylic acid groups appear on the surface of MWNTs. Characterization of the functionalized MWCNTs using XRD, TEM, and TGA show that the MWCNTs are opened and their aspect ratio depends strongly on the acid treatment time. It was also found that the nitric acid for a 4 hours treatment duration led to the highest removal of the impurities with the least destructive effect. | 9 3 |
| 17:15 | Graphene Coated Electrodes for Direct Oxidation of Endocrine Disrupting Chemicals Authors : Qijin Wan,†,* Hui Cai,† Yi Liu,† Hongtu Song,† Hualing Liao,† Xiaoxia Wang,§ Nianjun Yang‡,* Affiliations : † School of Chemical Engineering & Pharmacy, Key Laboratory for Green Chemical Process of Ministry of Education, Hubei Key Lab of Novel Reactor & Green Chemical Technology, Wuhan Institute of Technology, Wuhan 430073, China § Blumenstrasse 6, Gundelfingen 79194, Germany ‡ Fraunhofer-Institute for Applied Solid State Physics (IAF), Freiburg 79108, Germany Resume : Graphene as a new electrode/transducer material, graphene has been paid extensive attention recently for electrochemical and biochemical applications. While the different between multi-layer graphene and graphite, the application of multilayer graphene coated electrodes for the detection of endocrine disrupting chemicals (EDCs) was seldom reported. EDCs, also called endocrine disruptors, are exogenous substances that act like hormones in the endocrine system and therefore disrupt the physiologic function of endogenous hormones. They exist widely in nature, artificially made products, and also widely used.
In this contribution, the multi-layer graphene coated electrode, graphite electrode, the carbon nanotube coated electrode, and glassy carbon electrode were utilized for electrochemical oxidation of 4-nonylphenol, one of EDCs. On the graphene coated electrode, electrochemical oxidation of other EDCs such as 2,4-dichlorophenol, bisphenol A, and octylphenol in the absence/presence of 4-nonylphenol was further studied. Electrochemical oxidation of 4-nonylphenol occurred at 0.61 V on the graphene coated electrode. This irreversible oxidation process was controlled by the adsorption of 4-nonylphenol. The anodic peak current was linear with the concentration of 4-nonylphenol in the range of 0.1 µM to 10 µM. The detection limit was 30 nM. The graphene coated electrode was applied successfully as an electrochemical sensor for the detection of 4-nonylphenol in water samples. | 9 4 |
| 17:15 | One-step reduction and functionalization of graphene oxide sheets Authors : Izabela Kaminska,1,2 Qi Wang,1 Manash R. Das,3 Yannick Coffinier,1 Joanna Niedziolka-Jonsson,2 Patrice Woisel,4 Joel Lyskawa,4 Marcin Opallo,2 Sabine Szunerits1 and Rabah Boukherroub1 Affiliations : 1Institut de Recherche Interdisciplinaire (IRI), CNRS USR 3078, Universit?e Lille1, Parc de la Haute Borne, 50 avenue de Halley, BP 70478, 59658 Villeneuve d'Ascq Cedex, France. 2 Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland 3 Materials Science Division, North East Institute of Science and Technology (NEIST), CSIR, Jorhat 785006, Assam, India 4 USTL, Unit?es Mat?aux Et Transformations (UMET, UMR 8207), Equipe Ing?erie des Syst?s polym?s (ISP), F-59655 Villeneuve d’Ascq Cedex, France Resume : Graphene has attracted a great deal of scientific and technological attention in recent years due to its unique electronic, mechanical and thermal properties. It has shown great promise for applications in different areas such as electronics, energy storage and conversion as well as in the development of biosensors [1-3].
Despite the many potential applications that graphene promises to offer, one of the major challenges remains the development of controlled functionalization schemes of graphene [4]. Chemical modification of graphene enhances its solubility, but also allows the electronic properties of the material to be controlled. Both covalent and non-covalent strategies have been used for graphene functionalization [4].
Here, we first describe an original strategy allowing simultaneous reduction of graphene oxide (GO) to graphene and its functionalization with azide-terminated dopamine. The azide function of the resulting graphene/dopamine composite films allowed in a follow up step the use of the copper(I)-catalyzed 1, 3-dipolar cyloadditon to “click” alkyne-terminated molecules to the interface [5].
We have then developed a one step process for the preparation of switchable graphene/tetrathiafulvalene (TTF) nanocomposite surfaces. We show that graphene/TTF nancomposites are readily formed through the addition of TTF to GO at room temperature at neutral pH. Chemical oxidation of TTF to TTF2 using an aqueous solution of Fe(ClO4)3 expels the charged molecule from the graphene nanosheets, while subsequent immersion in neutral TTF solution allows the capture of the TTF molecules [6].
Finally, we report on simultaneous detection of L-dopa and carbidopa at neutral pH by differential pulse voltammetry on a graphene modified GC electrodes [7].
[1] Novoselov, K. S.; Geim, A. K.; Morozov, S. V.; Jiang, D.; Zhang, Y.; Dubonos, S. V.; Grigorieva, I. V.; Firsov, A. A., Science 2004, 306, 666-669.
[2] Allen, M. J.; Tung, V. C.; Kaner, R. B., Chem. Rev. 2009, 110, 132.
[3] Li, L. X.; Zhang, G. Y.; Bai, X. D.; Sun, X. M.; Wang, X. R.; Wang, E.; Dai, H. J.,
Science 2008, 319, 1229.
[4] Liu L.-H.; Yan, M. J. Mater. Chem. 2011, 21, 3273.
[5] Kaminska, I.; Das, M. R.; Coffinier, Y.; Niedziolka-Jonsson, J.; Woisel, P.; Lyskawa, J.; Opallo, M.; Boukherroub, R.; Szunerits, S. ACS Appl. Mater. Interf. 2012 (in press)
[6] Kaminska, I.; Das, M. R.; Coffinier, Y.; Niedziolka-Jonsson, J.; Woisel, P.; Opallo, M.; Szunerits, S.; Boukherroub, R. Chem. Commun. 2012, 48, 1221-1223. (Cover page)
[7] Wang, Q.; Das, M. R.; Li, M.; Boukherroub, R. Szunerits, S. Bioelectrochemistry (2012). | 9 5 |
| 17:15 | Chromatographic Separation of Highly Soluble Nanodiamond Prepared by Polyglycerol Grafting Authors : Li Zhao, Tatsuya Takimoto, Naoki Komatsu Affiliations : Department of Chemistry, Shiga University of Medical Science Seta, Otsu 520-2192 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 the purpose, ND should first form a stable hydrosol under a physiological environment. In order to increase the solubility, we change the surface functionality of ND from conventional linear polyethers (PEG) [1] to hyperbranched polyglycerols (PG). We choose the PG functionality for the following reasons: high hydrophilic property, biocompatibility, hyperbranched structure and easy functionalization. As a result, the PG grafted ND (ND-PG) exhibited extremely high solubility (16 mg/mL) in phosphate buffer saline (PBS) [2].
The solubilized ND-PG passed through silica-based columns in the size exclusion chromatography (SEC) under a flow of a pH 7.0 buffer as a mobile phase [2]. The scanning transmission electron microscopy (STEM) and dynamic light scattering (DLS) measurements of the fractions reveal that ND-PG is successfully separated according to their sizes. Size-sorting of ND-PG by SEC is believed to make a great progress in view of cancer imaging utilizing enhanced permeability and retention (EPR) effect in solid tumors.
[1] T. Takimoto, N. Komatsu, Chem. Mater., 22 (11), 3462-3471 (2010).
[2] L. Zhao, N. Komatsu, Angew. Chem. Int. Ed., 50 (6), 1388-1392 (2011) | 9 6 |
| 17:15 | Optical Resolution of Single-Walled Carbon Nanotubes through Molecular Recognition with Chiral Diporphyrin Nanotweezers Authors : Gang Liu, Feng Wang, Xiaobin Peng, A. F. M. M. Rahman, Naoki Komatsu Affiliations : Department of Chemistry, Shiga University of Medical Science, Seta, Otsu 520-2192, Japan Resume : Although much effort has been directed toward selective synthesis and separation of SWNTs with limited structures or specific properties, optical activity originating from carbon nanotubes themselves has been elusive. Here we designed and synthesized chiral diporphyrins consisting of two porphyrin units and rigid spacer in between, and used them to obtain optically active SWNTs through molecular recognition of the helical isomers of SWNTs. SWNTs were separated as follows. After SWNTs (CoMoCAT) in methanol were bath-sonicated in the presence of (R)- or (S)-diporphyrin, the suspension was centrifuged to give black supernatant. The diporphyrins were completely removed from the complexes by washing with pyridine several times. The SWNTs free from the diporphyrins were dissolved into D2O with the aid of SDBS and the solutions were analyzed with circular dichroism (CD). The solutions of SWNTs extracted by (R)- and (S)-diporphyrins showed symmetrical CD spectra, indicating that two stereoisomers (R and S) of each diporphyrin preferentially extract SWNTs with opposite helicities (M and P) and that the SWNTs extracted are optically active. In addition to the optical enrichement, (n, m) abundance of SWNTs was changed after the extraction. Our nanotweezers recognize not only helicity, but also (n,m) structures of SWNTs.
Reference: X. Peng, N. Komatsu, Nature Nanotechnology, 2 (6), 361-365 (2007).
F. Wang, N. Komatsu, J. Am. Chem. Soc., 132 (31), 10876-10881 (2010). | 9 7 |
| 17:15 | Parameters and Methods of Characterization of Commecial Nanodiamonds Authors : I. Petrov, O. Shenderova, N. Petrova Affiliations : SKN, Snezinsk, Russia; International Technology Center, Raleigh, 27714, USA; South Ural State University, Chelyabinsk, Russia Resume : Since first nanodiamonds (ND) were obtained in USSR in 1963, this material was widely used in numerous applications and its production expanded. However, there was no a generally accepted system of classification and methods of determining its parameters. Producing of ND is a complex process, it is necessary to characterize the product after each production phase. As a result of the first stage (synthesis) nanodiamond soot is obtained. Depending on the way of synthesis, the soot varies in the amount of incombustible impurities (5-25%) and non-diamond carbon phase (25-65%). After the second stage (purification) the content of impurities decreases: 0.3-5% of incombustible residue and 0.3-5% of non-diamond carbon, according to the data presented by different producers. However, these numbers can be inadequate because of absence of universal measurement technique. Besides, depending on an area of applications, the above-mentioned standardization parameters are not enough. The size of primary ND particles and chemically connected aggregates, size and sedimentation stability, surface modifications and crystal lattice defects, which can be measured with modern devices, should be considered. Any influence on the material throughout the process of production and modification effects on possibilities of using the product. The main existing methods of characterization of ND during the production process are considered. | 9 8 |
| 17:15 | Functionalization of carbon related materials (CNT and PET) by nitrogenated microwaves plasma for biomedical and renewable energy applications Authors : M.C Boisse-Laporte1, X. Cheng2, B. Lepoittevin3, J. Casimiro3, P. Roger3, H. Perez2, M. Pinault2, M. Mayne-L’hermite2, O. Leroy1, P. Jegou4, B. Bouchet-Fabre2 Affiliations : 1 Laboratoire Francis Perrin, CEA-Saclay/CNRS, IRAMIS/SPAM, 91191 Gif sur Yvette Cedex, France 2 Laboratoire de Physique des Gaz et des Plasmas, Bat 210, Université Paris Sud, 91405 Orsay Cedex, France 3Laboratoire d’Etude des Matériaux Hors Equilibre, ICMMO, Bat 410, Université Paris-Sud, 91405 Orsay Cedex France 4Laboratoire de Chimie des Surfaces et Interfaces, CEA-Saclay/CNRS, IRAMIS/SPCSI, 91191 Gif sur Yvette Cedex, France Resume : For the biomedical applications the surface of carbon materials such as Poly(ethylene terephthalate) (PET), has to be improved because of its hydrophobicity, low surface energy and poor wettability, which causes issues of bacterial contamination when it is in contact with natural fluid. A way to enhance the performance of the carboneous surfaces is to introduce functional groups on their surfaces by means of a plasma functionalization.
Besides biomedical application Nitrogen functionalized carbon nanotubes (CNT) have been reported as electro-catalyst for oxygen reduction which is a reaction of interest in fuel cell technology.
Similar microwaves plasma has been applied to PET films and CNT carpets; two methods were compared consisting in the use of ammonia NH3 or a combination of nitrogen and hydrogen N2/H2 at low pressure microwave plasma. The plasma parameters were optimized on the reactor to increase the primary amino groups –NH2 density at the surface of the PET, which was estimated by XPS analysis and by colorimetric titration [1].
The spectroscopic analysis reveals differences in the functionalization of both kind of surfaces, in relation with the different carbon sp2 and sp3 configurations. A comparison will be done for the different materials on the efficiency of the treatment by NH3 or N2/H2 plasma. Preliminary investigation related to oxygen reduction will be presented for the functionalized CNT.
[1] JJ. Casimiro, B. Lepoittevin, C. Boisse-Laporte, M.-G. Barthés-Labrousse, P. Jegou, F. Brisset, P. Roger, Plasma Chem. & Plasma Proc. (2012) in press | 9 9 |
| 17:15 | Multi-walled carbon nanotubes generate the reactive oxygen species under NIR irradiation Authors : S.V. Prylutska, A.P. Burlaka, S.M. Lukin, Yu.I. Prylutskyy, U. Ritter, P. Scharff Affiliations : Kyiv National Taras Shevchenko University, Volodymyrska Str., 64, 01601 Kyiv, Ukraine; R.E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology, NAS of Ukraine, Vasylkivska Str., 45, 03022 Kyiv, Ukraine; V.Ye. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine, Nauky Ave., 41, 03028 Kyiv, Ukraine; Ilmenau University of Technology, Institute for Chemistry and Biotechnology, Weimarer Str., 25, 98693 Ilmenau, Germany Resume : The ability of highly purified multi-walled carbon nanotubes (MWCNTs) to catalyze the reactions for the generation of reactive oxygen species (ROS) in water suspension at low concentration (1 mcg/ml) after a brief exposure of NIR irradiation was demonstrated. ROS levels were registered using the methods of EPR spectroscopy and spin traps. The effect of a self-induced ROS generation after photoirradiation of MWCNTs has been observed. The revealed phenomenon opens the real perspective for using photoirradiated MWCNTs in photodynamic therapy of tumors as an effective ROS catalytic system. | 9 10 |
| 17:15 | Luminescent properties of carbon nano-dots incorporated in porous silicon oxide matrix Authors : A.V. Vasin*, S.O. Gordienko*, A.V. Rusavsky*, A.N. Nazarov*, V.S. Lysenko*, Yu.P. Piryatinski**, I.V.Blonsky**, E. Makila***, J.Salonen***, S. Prucnal****, L. Rebohle****, W. Skorupa**** Affiliations : *Lashkaryov Institute of Semiconductor Physics, pr. Nauki 41, Kiev 03028, Ukraine; **Institute of Physics, pr. Nauki 46, Kiev 03028, Ukraine; ***Department of Physics, University of Turku, Turku FI-20014, Finland; ****Institut fur Ionenstrahlphysik und Materialforschung, Helmgolz-Zentrum Dresden Rossendorf e.V., Dresden, Germany Resume : Physical mechanism of visible photoluminescence in carbon nano-dots is still under discussion. In present report the light-emitting carbon nano-dots incorporated in porous silicon oxide layers (por-SiO2:C) were fabricated by thermal treatment of porous silicon in flow of acetylene (1100-1300 K) followed by oxidation in flow of wet argon (900-1000 K). Por-SiO2:C layers exhibited strong white photoluminescence (PL) with broad spectrum covering all visible range. Maximum of PL intensity was shifted from green to orange with increasing of carbonization temperature. It is interesting that spectral properties of PL of por-SiO2:C can be tuned almost ideally to that of natural white light of the scattered day sun irradiation opening a new application prospective for this material. It is shown that degradation of PL efficiency under ultraviolet radiation is associated with photo-induced interaction (probably oxidation) of carbon material with atmospheric oxygen and can be avoided by encapsulation of the material. Luminescent properties of por-SiO2:C layers were studied at temperature range of 20-420 K. It is shown that in temperature range of 20-300 K the PL intensity is almost constant indicating a strong localization of photo exited carriers. Farther increase of the temperature up to 420 K resulted in drastic increase of the light emission efficiency. Physical mechanisms of temperature dependent PL evolution will be discussed. | 9 11 |
| 17:15 | Investigation of the spontaneous grafting of polycyclic aryldiazonium salts at carbon surfaces Authors : Deirdre M. Murphy, Ronan J. Cullen, Dilushan R. Jayasundara, Eoin M. Scanlan, Paula E. Colavita Affiliations : School of Chemistry, University of Dublin Trinity College, College Green, Dublin 2, Ireland Resume : Modification of surfaces via aryldiazonium salts is widely used to covalently link aryl groups to a variety of substrates. Aryldiazonium cations can be grafted at surfaces either via electroreduction, or spontaneously from solution. Spontaneous grafting is particularly advantageous when it is not possible or desirable to make electrical contact with the surface and it has allowed researchers to extend the application of aryldiazonium chemistry to surface modification of insulating materials and nanoparticles in suspension. For this reason there is great interest in understanding and controlling the kinetics of spontaneous grafting. In this work we have focused on investigating the adsorption kinetics of polycyclic aryldiazonium salts and how their grafting rate and yield depends on the structure and stability of the salt.
We report, for the first time, on an in situ study of the spontaneous attachment of two polycyclic aromatic positional isomers at amorphous carbon surfaces. The grafting process was monitored in real time via infrared spectroscopy at the carbon/liquid interface and ex situ via electrochemical methods, showing significantly different adsorption rates for the two molecules. The two isomers were found to be equally stable towards dediazotization under the grafting conditions, suggesting that differences in absorption rate must arise from structural differences: in particular a difference in electron density at the diazocarbon of these positional isomers. | 9 12 |
| 17:15 | Synthesis of ionic liquid-grafted graphene oxide and its application in direct electrochemistry of horseradish peroxidase Authors : Yanhui Ma,Guoqing Zhan, Chunya Li* Affiliations : Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission, College of Chemistry and Materials Science, South–Central University for Nationalities, Wuhan 430074, China Resume : N-(3-Aminopropyl) imidazole grafted graphene oxide (NAI-GO) sheets were successfully synthesized via amidation reaction. Then, NAI-GO sheets were reacted with alkyl bromide to produce imidazole ionic liquid grafted graphene oxide sheets (IMIL-GO). The obtained IMIL-GO was well characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and infrared (IR) spectra. IMIL-GO was found well dispersed into aqueous solution. Horseradish peroxidase (HRP) was immobilized onto an IMIL-GO modified glassy carbon electrode. The direct electrochemistry of HRP immobilized on IMIL-GO electrode was investigated by cyclic voltammetry (CV). The CV results showed that the HRP-IMIL-GO modified electrode gave rise to well-defined peaks in phosphate buffer, corresponding to the electrochemical redox reaction between HRP–Fe (III) and HRP–Fe (II). The obtained HRP-IMIL-GO electrode also displayed an electrocatalytic reduction behavior towards H2O2. | 9 13 |
| 17:15 | Biofunctionalization of carbon nanotubes with chlorophyll-containing biomimetic membranes for biomedical applications Authors : Marcela Elisabeta BARBINTA-PATRASCU, Tudor MITRAN, Laura TUGULEA Affiliations : University of Bucharest- Faculty of Physics, 405, Atomistilor Street, Postal Code: RO- 077125, Magurele, judet Ilfov, ROMANIA Resume : The development of new advanced biomaterials with interesting properties have attracted much more attention in the recent years. This work presents a new bottom-up approach strategy to design noncovalent entities based on carbon nanotubes and liposomes, with potential biomedical applications (drug delivery systems).
The photosynthetic pigment chlorophyll a, a magnesium derivative of porphyrins, was incorporated in liposomes as a molecular sensor to monitor the changes occurred in the artificial lipid bilayers. Liposomes are lipid vesicles that can be formed spontaneously when lipids are dispersed in aqueous solutions, the inner volume being surrounded by a membrane made of a lipid double layer, structure that mimics the cell membranes. Due to their ability to encapsulate hydrophilic or lipophilic agents, liposomes are used as drug delivery systems.
The interaction between liposomes and carbon nanotubes is facilitated by the intervention of chlorophyll a which is inserted into the artificial lipid bilayers. These nanobiomaterials were investigated by different physical methods: absorption and emission UV-VIS spectroscopy, dynamic light scattering analysis (DLS), scanning electron microscopy (SEM).
The biofunctionalization of carbon nanotubes with biomimetic membranes could be an effective method to increase CNT biocompatibility and to reduce their toxicity, getting bionanocomposites with potential use in medical therapies. | 9 14 |
| 17:15 | Biocompatibility of carbon-iron based nanoparticles assessment by flow citometry using human red blood cells Authors : F. Dumitrache 1, C. Fleaca 1 , A. Rugina 2, A-M. Gheorghe 2 , A.L. Ciotec 2, R. Alexandrescu 1 , C. Luculescu 1 , L. Gavrila-Florescu 1, I. Voicu 1 , I. Morjan 1, D. Bratosin 2, 3 Affiliations : 1. National Institute for Laser Plasma and Radiation Physics, 409 Atomistilor, 072125, P.O. Box MG 36, Magurele, Romania; 2. National Institute for Biological Science Research and Development, 296 Spl. Independentei, 060031-Bucharest, Romania; 3. ”Vasile Goldis” Western University of Arad , Faculty of Natural Sciences, 91-93 Liviu Rebreanu, 310414 - Arad , Romania Resume : Turbostratic Carbon, F, N and S doped C and Fe/ Fe3C core-C shell nanoparticles where produced by laser pyrolysis and tested in contact with human red blood cells (RBCs). The biocompatibility was evaluated by temporal evolution and cellular dynamics of RBCs in contact with physiological buffer saline nanoparticles dispersion. The nanoparticles were analyzed using TEM, SAED, XRD and EDX. In the case of Fe-based samples magnetic analysis were performed and the sample with the highest saturation magnetisation value (120 emu/g) was selected. The nanoparticles agglomeration level in water based dispersions was evaluated by DLS. Only dispersions with stable values during DLS measurements and dynamic diameter less than 200 nm were selected for biocompatible tests. For assessing cytotoxicity of nanoparticles we developed a new experimental cell system based on the use of RBCs which are directly exposed to different concentrations of nanoparticles and we have evaluated the toxic effects after 3 and 24h incubation endpoints for morphological changes (FSC/SSC), apoptosis/necrosis analysis (FITC-annexin-V labeling/PI) and viability (using calcein-AM method) by flow cytometric analysis. Flow cytometric analysis of RBCs viability and cell death discrimination (erythroptosis) could provide a rapid and accurate analytical tool for evaluating in vitro the biological responses against nanoparticles. Our results show a good compatibility in the cases of Fe-C and turbostratic C nanoparticles. | 9 15 |
| 17:15 | Study of Ohmic Contact formation on diamond surfaces Authors : J.-C. Gerbedoen(1), G. Patriarche(2), C. Mer-Calfati(3), J.-C. Arnault(3), A. Soltani(1), J.-C. De Jaeger(1) Affiliations : (1) IEMN UMR CNRS 8520, USTL PRES Université Lille Nord de France, France; (2) LPN-CNRS, 91460 Marcoussis, France; (3) CEA-LIST, Diamond Sensors Laboratory, 91191 Gif-sur-Yvette cedex, France; Resume : This work describes the study of ohmic contact formation on homoepitaxial CVD p-doped diamond substrate permitting to understand the ohmic contact behaviour at the surface. The structure is composed of a buried -doped layer on Ib diamond substrate. Ti/Pt/Au metallisation is used for the ohmic contact realisation. The transport properties and the ohmic contact characteristics are obtained from Hall Effect and current-voltage measurements respectively. XPS, EDX and HRTEM measurements are performed to investigate the ohmic contact structure. The stoichiometry of the different compounds is deduced from EDX measurement. Different alloys are observed. They are composed of Ti, O, Pt, Au, Cr and Ni. HRTEM observations show an abrupt interface between Ti and diamond surface after ohmic contact annealing. However, measurement shows that no carbide formation is formed at the interface such as TiC but different alloys such as AuPt and TiPt are formed. Furthermore, it is seen that O move to the interface Metal/Diamond. The metallization does not diffuse in the diamond. The STEM pictures showed no structural defects associated with the B doping. After the ohmic contact removal by acid solution, XPS measurement is performed to check if TiC is present at the surface. The atomic concentration of Ti is under the XPS detection limit. No TiC bind is observed between 281.3eV and 282eV at C1s core level. HRTEM and XPS investigations confirm that there is no TiC at the Metal/diamond interface. | 9 16 |
| 17:15 | Investigation of Wear Properties of TiO2 /DLC Coating on Ti6Al4V Alloy Using a Combined Technique of Micro Arc Oxidation Process and PVD Authors : 1-Ebru Emine DEMIRCI, 2-Ersin ARSLAN 3-Yasar TOTİK 4-Ozlem BARAN 5-Ihsan EFEOGLU Affiliations : 1-3-5: Department of Mechanical Engineering, Atatürk University, 25240, Erzurum, Turkey, 2: Erzurum College of Vocational, Atatürk University, 25240, Erzurum, Turkey. 4: Department of Mechanical Engineering, Erzincan University, 24100, Erzincan, Turkey Resume : Micro arc oxidation (MAO) is an effective technique to improve the surface properties of light materials by forming ceramic films on the surface. A number of studies have been carried out for depositing on Ti and Ti alloys by using MAO. However, only a few have focused on wear properties and duplex coatings treatment. In this study, the combined MAO and physical vapour deposition (PVD) process was used to deposit duplex MAO/DLC coating on Ti6Al4V alloy. The microstructures, morphology and composition were analyzed by scanning electron microscope (SEM) and Raman spectroscopy. The wear properties of the duplex coatings were investigated by scratch tester. The results showed that the Ti-doped DLC thin film could be successfully deposited onto the MAO coating and it also showed that MAO coating has an important role on the wear properties of Ti6Al4V samples that are coated by duplex coating. It was found that the duplex MAO/DLC coating shows better wear properties than the DLC or MAO monolayer on Ti6Al4V samples. | 9 17 |
| 17:15 | Combined in situ and ex situ characterization of diazonium salt chemisorption at gold and carbon surfaces Authors : Dilushan R. Jayasundara, Ronan J. Cullen, Laura Soldi, Paula E. Colavita Affiliations : School of Chemistry, University of Dublin Trinity College, College Green, Dublin 2, Ireland. Resume : Modification of solid surfaces with diazonium salt derived aryl layers has attracted much attention primarily due to its high stability and resistance to long time ambient exposure. Furthermore, the ability to spontaneously graft with high yield on many substrates provides a much simpler and more versatile method for surface functionalisation that finds applications in surface micropatterning, biosensing and molecular electronics. This has generated interest in understanding the mechanism of this reaction, with the aim of achieving control over structure and coverage of these solid/organic interfaces.
In this study we use a combination of quartz crystal microbalance, cyclic voltammetry, infrared reflection absorbance spectroscopy and X-ray photoemission spectroscopy to monitor the grafting process as well as to characterize the derived layers at different stages of their growth on both gold and carbon surfaces. On gold surfaces, the concentration dependence of the grafting rate was best modeled by a reversible Langmuir model. The free energy of adsorption obtained, combined with the ex situ measurements indicates a physisorption as the first kinetic step in the grafting of aryl diazonium salts onto the gold surface. In the case of carbon, the adsorption rate is lower than on gold and also depends on the sp2 content of the carbon substrate. Furthermore, X-ray photoemission spectroscopy studies show a higher yield for nitrophenyl groups on the surface of carbon than that observed on gold. Finally we discuss the implications of our results for understanding the surface chemistry of these materials while giving practical guidelines for controlled deposition of these organic layers. | 9 18 |
| 17:15 | Surface nitridation of CVD Nanocrystalline Diamond Films by Low Energy RF-Plasma with Different Gas Compositions Authors : D. Ballutaud1†, S. Saada2, B. Bouchet-Fabre3 Affiliations : 1 GEMaC-CNRS, 92195 Meudon cedex, France 2 CEA-LIST, Diamond Sensor Laboratory, F-91191 Gif-sur-Yvette, France 3 CEA-IRAMIS, Laboratoire Francis Perrin, CNRS URA2453, F- 91191 Gif-sur-Yvette, France †present address : 164 av. J. Jaures, 92140 Clamart Resume : The control of diamond surface chemistry is of fundamental importance for new high power / high temperature micro-electronic devices, as well as for controlling further amination of the diamond surface. In particular, the surface of diamond may be functionalized with nitrogen containing groups, for biotechnological applications, i.e. biomolecule immobilization.
For this presentation, nanocrystalline diamond thin films with two different grain sizes (50 nm and 300 nm) were grown on Si substrates by chemical vapor deposition ; their surfaces were nitrided at room temperature by immersion in low energy RF plasma (0.05 W.cm-2). Three different plasma gas compositions are used: pure nitrogen, mixture of hydrogen and nitrogen, or mixture of ammonia with hydrogen and nitrogen. The resulting carbon and nitrogen bonding are characterized using X-ray photoelectron spectroscopy (N1s, C1s) and the modification of the superficial carbon phases are analyzed by Raman spectroscopy.
The dominant part of the N1s core level shows two main components (398.8 and 400.4 eV) attributed to sp3 C=N and sp2 C-N bonds, respectively. The relative intensity of these components depends on the plasma conditions.
Moreover the atomic ratio N/C at the nano-diamond surface is depending on the plasma composition and the nano-diamond grain size. It may reach 0.16 for the best condition | 9 19 |
| 17:15 | Functionalized graphene oxide for high efficient gene delivery into insect cell lines with low cytotoxicity Authors : Jing Zhang, Liangzhu Feng, Zhuang Liu, Rui Peng Affiliations : Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou, Jiangsu, P. R. China Resume : The development of safe and highly efficient gene delivery carriers is critical for both gene therapy and cell researches. Graphene oxide (GO) has been shown to function as efficient gene delivery reagent, yet most work have been done with adherent cell lines. In this work, GO functionalized with polyethylene glycol (PEG) and polyethyleneimine (PEI) (GO-PEG-PEI) was developed for high efficient gene delivery into semi-adherent cell lines, which are usually difficult to transfect even using commercial transfection reagents suitable for sensitive cell lines. A widely used insect cell line, Drosophila S2 cell, was chosen as the model. Using a plasmid encoding the green fluorescence protein (GFP) as report gene, we show that positively charged GO-PEG-PEI is highly efficient in DNA packing and DNA delivery into S2 cells. Flow cytometry analysis showed that up to 70% of the cells were successfully transfected by GO-PEG-PEI in 10% serum media, while only around 30% transfection efficiency was achieved when two commercial reagents (Lipofectamine 2000 and Effectene) were used. Transfection of linear DNA fragments was examined as well. Again, GO-PEG-PEI exhibited almost 8 fold higher efficiency than that of Lipofectamine 2000. S2 cells treated with GO-PEG-PEI for 24 h maintained over 90% viability, further demonstrating the potential of this functionalized GO as a highly efficient gene nano-carrier with low cytotoxicity. | 9 20 |
| 17:15 | An investigation of the spontaneous grafting of aryldiazonium salt onto disordered carbons Authors : Ronan J. Cullen, Dilushan R. Jayasundara, Laura Soldi, Jayce J. Cheng, Gaelle Dufaure, and Paula E. Colavita. Affiliations : School of Chemistry, Trinity College Dublin, Dublin 2, Ireland. Resume : Disordered carbon materials have numerous applications ranging from everyday objects such as piping and toner to more technologically advanced items such as implantable biomedical devices. Despite being of great interest to numerous areas, little is known of the chemistry that these materials display. Given that many of their applications rely on interactions that take place at their surface, an understanding of surface chemistry and how the composition of these materials might affect said chemistry is of great interest. In this work we investigated a reaction that is important for modulating carbon surfaces, the spontaneous adsorption of aryldiazonium salts.
Amorphous carbons were deposited in the form of thin films via reactive magnetron sputtering, and were characterized using a combination of Raman, infrared, UV-Vis and X-ray Photoelectron Spectroscopy in order to determine their sp2 content. Attenuated Total Internal Reflection Fourier Transform Infrared spectroscopy was used to monitor in situ the aryldiazonium adsorption process at the carbon/solution interface. Grafting as a function of time was also monitored ex situ via cyclic voltammetry. Our measurements demonstrate that grafting rates and yields increase non-linearly with an increase in sp2 content. We discuss the significance of these results for the development of structure/reactivity relationships which will lead to an increased understanding of the chemical processes which occur at disordered carbon surfaces. | 9 21 |
| 17:15 | ZnO-coated carbon nanotubes: An Shifted Emssion band Authors : Chia-I Hung, Hua-Chiang Wen, Hsin-Jung Tsai, Wen-Kuang Hsu* Affiliations : Department of Materials Science and Engineering, National Tsing Hua University Resume : Carbon nanotubes (CNTs) are graphene sheets rolled into seamless cylinder and display an excellent flexibility in perpendicular to tube axis. For example, the brittle oxides (e.g. ZnO), as deposited onto cushioning CNTs, do not fracture with repeated deflections. ZnO known as piezoelectric crystal also emits light at ultraviolet (UV) wavelength and the emission center has been identified arising from optical transition at the near-band edges (NBE)
In this work, multi-walled CNTs (MWCNTs) are coated with ZnO using atomic layer deposition (ALD) and intensity of oxide luminescence is found increasing by a factor of 2.5. Sample then be annealed at 500℃. Compared the cathodoluminescence spectra (CL), XRD and Photoluminescence Spectra (PL) results between as-synthesized products and annealed one, it appears that some interesting things. First, in XRD diffraction pattern, the (110), (113) and (018) peak indicate the ZnCO3 formation in sp2 hybridized networks. Zn replacement by C, which results in Zn-C bond formation, this can be proved by Auger mapping graph, it indicate that the Zn decreases as C increases at t=15-18 min, besides, by ab-initio calculation, the results in Eg reduction also be consistent with the PL spectra.
Second, in CL parts, as-synthesized product (ZnO/CNT) was found that different from ZnO nanowire in room temperature, the graph close to a horizontal straight line. And at low temperature 20K, the emissions are composed of four peaks, besides three typical peaks | 9 22 |
| 17:15 | Correlation between time resolved photoluminescence and infrared absorption spectra of functionalized nanodiamond surface Authors : Z. Remes, H. Kozak, M. Perlik, A. Kromka Affiliations : Fyzikální ústav AV ČR, v. v. i., Cukrovarnická 10/112, 162 00 Praha 6, Czech Republic Resume : Functionalized nanodiamond differs significantly in surface properties such as electrical conductivity, electron affinity, wettability and chemical reactivity. For functionalization technology as well as for further applications, precise identification of chemical groups on the functionalized NDs is important. Recently, we presented a novel tools of grazing angle reflectance (GAR ) and attenuated total reflectance (ATR) Fourier transform infrared spectroscopy (FTIR) employing diamond-coated metallic mirrors and silicon prism for enhancing sensitivity, resolution and repeatability of the IR absorption spectra characterizing nanodiamond surface moieties, in particular on plasma-oxidized and plasma-hydrogenated nanodiamonds. We have also contributed recently to shown that electronic relaxation processes in femto- and picosecond range with the excitation by photons with energy smaller than the diamond band-gap energy provides a powerful tool for studying dynamics of electrons in the energy states connected with the surface and boundaries of diamond nanocrystals. Here we correlate the time resolved photoluminescence in nano- and microsecond scale with the infrared absorption spectra of functionalized (carboxylated, hydroxylated, hydrogenated ) nanodiamond surface. We kindly acknowledge the support of the GACR project P108/12/G108 | 9 23 |
| 17:15 | Carbon Nanotubes Functionalized by Cold Plasma Jet in Liquids Authors : Marek Eliáš, Lenka Zajíčková, Miloš Klíma, Věra Mazánková Affiliations : Central European Institute of Technology and Department Physical Electronics, Masaryk University, Brno, Czech republic Resume : The functionalizaion of commercial CNTs purchased from Nanocyl was performed in a cold atmospheric pressure plasma jet, a
microplasma discharge that is ignited by rf voltage in the gas flowing through a narrow long capillary. The Nanocyl CNTs were dispersed in a liquid in ultrasonic bath and the jet was ignited in the liquid. We have tested the functionalization by Ar, Ar/N2 and Ar/O2 jets in distilled water and by the Ar jet in different concentrations of peroxide solutions (1%, 5%, 10% and 30%). The sedimentation of commercially functionalized CNTs and atmospheric pressure plasma functionalized CNTs dispersed in distilled water were compared on the time scale of days. The results showed a significant improvement in dispersion of CNTs funcionalized by an Ar/O2 jet in water and Ar jet in peroxide solutions. The best results were obtained for peroxide concentration of 1%. The functionalized CNTs were characterized by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). | 9 24 |
| 17:15 | Electrochemical functionalization of glassy carbon and application in monitoring COD level Authors : Can Wu, Qin Cheng, Kangbing Wu Affiliations : School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China Resume : Electrochemical functionalization of glassy carbon and application in monitoring COD level
Can Wu, Qin Cheng, Kangbing Wu *
School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
The glassy carbon electrode (GCE) was functionalized by electrochemical oxidation, and exhibited remarkable enhancement effect on the response signal of chemical oxygen demand (COD). After 5-min oxidation under 1.8 V in 0.1 M Na2HPO4, three-dimensional structures were introduced on the surface of the GCE. From the comparison of AFM images, it was found that the functionalized GCE became rough, providing numerous active sites and larger response area.
In addition, the surface group of functionalized GCE was characterized using Micro-FTIR, and an absorption peak at 3278 cm-1 that attributed to hydroxyl group was observed on the surface of functionalized GCE.
It is quite important to detect COD value because it indicates the organic pollution in water [1-3]. In this work, it was found that the electrochemically functionalized GCE greatly increased the response signal of COD. From the response signals of water samples with different COD values on the functionalized GCE, it is apparent that the oxidation signal of COD increases linearly with its concentration. As a result, a novel electrochemical method was developed for the detection of COD. The limit of detection is as low as 0.33 mg L-1. Finally, this method was used to detect COD values of different water samples, and the results consisted with the values that obtained by national standard method.
Acknowledgement
This work was supported by the National Basic Research Program of China (973 Program, No. 2009CB320300) and the National Natural Science Foundation of China (No. 61071052).
References
[1] S.Q. Zhang, L.H. Li, H.J. Zhao, Environ. Sci. Tech. 43 (2009) 7810-7815.
[2] J.Q. Yang, J.W. Chen, Y.K. Zhou, K.B. Wu, Sensors and Actuators B: Chemical 153 (2011) 78-82.
[3] Q. Cheng, C. Wu, J.W. Chen, Y.K. Zhou, K.B. Wu, The Journal of Physical Chemistry C 115 (2011) 22845-22850. | 9 25 |
| 17:15 | SURFACE MODIFICATION OF NANODIAMOND PARTICLES, TO FORM THE ALKYL CHAINS Authors : K. Adach1, J. Skolimowski2, K. Mitura1,3 Affiliations : 1 Technical University of Lodz , Lodz, 1/15 Stefanowskiego st., Poland; 2 University of Lodz, Łodz, Department of Organic Chemistry, 12 Tamka st., Poland. ; 3Koszalin University of Technology, Koszalin, 2 Sniadeckich st., Poland. Resume : Diamond nanopowders due to its properties may form ideal biomaterial for biomedical applications. They are also susceptible to chemical modifications, and due to their surface ability to connection with many of organic groups, that can affect properties their surface [1]. Via further purification the surface of nanopowders, can affect the rate and efficiency of the process in subsequent modifications. These two main features namely: biocompatibility of the nanodiamond with the tissues and the ability to modify may allow to application of these materials in biomedical engineering [2,4]. Accurate understanding and analysis of processes occurring during chemical synthesis constitute a basis for understanding the phenomena of reaction mechanisms during further modification [3]. Nanodiamonds have a developed surface area, which can be modified using chemical reactions. Currently the preparation of suitabley functionalized nanodiamonds with organic moieties to implement new properties on the otherwise inert nanodiamonds is a topic of much interest [5,6]. It was shown aggressive Fenton treatment can serve to remove in a considerable extent undesirable carbon material while at the same time increasing the density of hydroxyl groups on the surface. Considering the above precedents nanodiamonds can be used as anchorages for covalent bonds the alkyl chains or aromatic rings [5,6,8]. Fenton reaction is a process in which nanodiamonds are reacted with hydrogen peroxide and Fe (II) ion in strongly acidic conditions. The conclusion of the study was the fact that aggressive conditions were more favorable [4,6]. Additionally, strong acids cause the dissolution of the amorphous form of carbon [6]. It also found a decrease in the average size of diamond nanoparticles [6,7,8]. Reactions leading to the formation the alkyl chains and aromatic rings on the nanodiamond surface. It is possible to carry out such chemical synthesis in order to bond an antibiotic in a large distance from the nanodiamond surface. Such modifications carry out to increase the number of antibiotic molecules on the nanodiamond surface. For this purpose, the powder should be subjected to Friedel-Craft's reactions or reaction with trifluoromethanesulfonic acid. Carried out such a modification with an γ - aminobutyric acid obtaining a positive result of nanodiamond modification.
[1] Adach K., Skolimowski J., Mitura K., Chemical modification of nanodiamond particles produced by detonation method, Elektronika, 11, 2011, 84 – 86
[2] Dean Ho, Beyond the sparkle: The impact of nanodiamonds as biolabeling and therapeutic agents, ACS Nano, 3, 2009, 3825 - 3829
[3] Kruger A., Angew. Chem., Int. Ed. 45, 2006, 6426 – 6427
[4] Solarska K., Gajewska A., Skolimowski J., Woś R., Bartosz G., Mitura K., Effect of non-modified anod modified nanodiamond particles by Fenton re action on human endothelial cells, Journal of Achievements In Materials and Manufacturing Engineering, Vol. 43, 2, 2010, 603 - 607
[5] Martin R., Heydorn P. C., Alvaro M., Garcia H., General strategy for higk-density covalent functionalization of diamond nanoparticles using Fenton chemistry, Chem. Mater. 21, 2009, 4505 – 4514
[6] Martin R., Alvaro M., Herance J. R., Garcia H., Fenton – Treated Functionalized Diamond Nanoparticles as Gene Delivery System, NANO ACS, 4, 2010, 65 – 74
[7] Burleson T., Surface modification of nanodiamonds for biomedical application and analysis by infrared spectroscopy, Journal of Achievements in Materials and Manufacturing Engineering, 37, 2009, 258 – 263
[8] Krueger A., Liang Y., Jarre G., Stegk J., Surface functionalisation of detonation diamond suitable for biological applications, J. Mater. Chem., 2006, 16, 2322–2328 | 9 26 |
| 17:15 | PREPARATION OF CARBON POWDER OBTAINED BY RF PA CVD METHOD FOR CHEMICAL MODIFICATIONS Authors : R. Woś 1, J. Skolimowski 2, K. Mitura1,3 Affiliations : 1Technical University of Lodz, Institute of Material Science and Engeneering, Stefanowskiego 1/15, 90 – 924 Lodz, PL 2 University of Lodz, Department of Organic Chemistry, Tamka 12, 91 – 403 Lodz, PL 3Koszalin University of Technology, Institute of Mechatronics, Nanotechnology and Vacuum Technology, Sniadeckich 2, 75 – 620 Koszalin, PL Resume : The object of research is the carbon powder prepared by chemical vapor deposition in an electric field of radio frequency RF PACVD (Radio Frequency Plasma Asisted Chemical Vapor Deposition).This powder has amorphous built [1].Its a phase composition, mainly of mixture sp3 and sp2 bonds of carbon atoms . Both its documented biocompatibility and bioactivity [2](in vitro experience -influence of carbon powder by force reducing the ascorbic acid) prompted us to attempt to use carbon powder as a carrier for bioactive substances. This powder consists of grains in the shape of flakes the size of ≥ 100 nm. Given the biological applications, the first modification is a mechanical comminution of the grains, which will let us to increase the reaction surface. Carbon powder with reduced grain was subjected to trifluoromethanesulfonic acid, that its action is to change the structure of the powder. It involves increasing the accessibility to the surface of the powder (reactive sites ). Such prepared powder (cleaned by trifluoromethanesulfonic acid magic from other forms of carbon) was subjected to the Fenton reaction [3]with applying strong reagents which they are still clearing powder in order to increase the amount of OH groups formed on its surface. The positive effect of Fenton reaction gives us the opportunity to join a number of biologically active molecules, mainly antibiotics. The whole spectrum of performed modifications was carried out for the answer to a question, whether the active carbon powder in combination with the biologically active substance will be its the carrier or whether its presence will weaken the negative action of the bonded substance.
[1] S. Mitura Journal of Crystal Growth, 80(1987) 417-424.
[2] K. Bakowicz-Mitura, G. Bartosz, S. Mitura, Influence of diamond powder particles
on human gene expression, Surface & Coatings Technology 201 (2007) 6131-6135
[3]Martin R.,Alvaro M.,Herance J.R.,Garcia H.:Fenton-Treated Functionalized Diamond Nanoparticles as Gene Delivery System, NANO ASC,4(2010) 65-74 | 9 27 |
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