Nanomaterials, such as nanocomposites, nanorods, nanotubes and graphenes, are nowadays almost past the title “novel materials”, they have been widely investigated and used as either promising or already proven materials for various applications ranging from electronics and black body coatings to fuel cells and supercapacitors (1). Such advanced nanomaterials, independently of their chemical composition, are also used for the delivery of therapeutic agents, including biomolecules targeting disease sites, for bioimaging, or in general for biomedical engineering (2). Besides the production of CBNs by exfoliation, epitaxial growth, CVD processes, and many other methods, an important method nowadays concerns the use of plasmas. In general, plasma based processes are widely used for technological applications (3). They are employed in microelectronics (4), or for example for the deposition of functional coatings and nanosystems (5). In particular low temperature reactive plasmas with their distinctive non equilibrium character provide an excellent tool for the production of novel CBNs. They are nowadays widely used for the deposition of aligned nanotube carpets, nanowalls, the synthesis of graphene, and self-standing graphene, for the controlled production of nanoparticles and for example for the manufacturing of highly porous structured surfaces (6-10). Differences in the morphology of plasma produced CBNs are caused sometimes by a small changes of the process parameters, like small variations in pulse frequency (7) or temperature (6, 11). The control and the understanding of the plasma is therefore essential in order to control the synthesis of the targeted materials. This requires enhanced efforts in plasma modelling and plasma diagnostics.

This contribution focusses on the plasma based production of different kinds of conductive carbon based nanomaterials in particular on the production of carbon nanotubes, nanoparticles and nanowalls or free standing graphene. A common denominator of these materials concerns –besides their conductivity and their excellent mechanical characteristic - their large specific surface area a factor that is in particular important for applications in the field of biosensors. We will discuss in this presentation different plasma based synthesis methods. This discussion will include some critical questions concerning the importance of catalysts for the production of CBNs as well as the role of different sample pretreatment methods for the outcome of plasma based synthesis experiments. The synthesis of the different carbon materials is monitored during their growth by means of in-situ Raman-spectroscopy. A further ex-situ material analysis is performed by means of Near Edge X-ray Absorption Fine Structure Spectroscopy (NEXAFS), XPS and electron microscopy. An important aspect for bioengineering applications is related to the functionalization of the CBNs which is essential for the coupling of biomolecules to sensor surfaces. We will here report about plasma based functionalization methods and in particular about the correlation between the plasma characteristics (determined by plasma mass spectroscopy, electron density measurements, in situ FTIR) and the resulting surface functionalities.

Acknowledgments: This work was supported by CNRS Défi Interdisciplinaire NANO2013, ANR PlasBioSens, APR Capt’Eau and MEP Flexible. We gratefully acknowledge also HZB, Berlin, Germany, for the allocation of the beam time.

References

(1) V. A. Krivchenko, S. A. Evlashin, K. V. Mironovich, N. I. Verbitskiy, A. Nefedov, C. Wöll, A. Ya. Kozmenkova, N. V. Suetin, S. E. Svyakhovskiy, D. V. Vyalikh, A. T. Rakhimov, A. V. Egorov & L. V. Yashina, Scientific Reports (Nature) 2013, 4, 3.

(2) C. Cha, Su Ryon Shin, N. Annabi, M.R. Dokmeci, A. Khademhosseini, ACS Nano 2013, 7, 2891.

(3) S Samukawa. et al (2012) (Plasma roadmap) J. Phys. D: Appl. Phys, 45 253001.

(4) D. B. Graves, Plasma processing in microelectronics manufacturing AIChE J. 1989, 35, 1.

(5) K Ostrikov, and Shuyan Xu. “Plasma aided nanofabrication: from plasma sources to nanoassembly”, (2007) Wiley-vch Verlag GmbH&Co. Weinheim, Germany.

(6) E Tatarova, A Dias, J Henriques, A M Botelho do Rego, A M Ferraria, M V Abrashev, C C Luhrs, J Phillips, F M Dias, C M Ferreira, J. Phys. D: Appl. Phys. 2014, 47 385501.

(7) J. Berndt, E. Kovačević, I. Stefanović, O. Stepanović, S. H. Hong, L. Boufendi, J. Winter, Contrib. Plasma Phys. 2009, 49, 107.

(8) R. Ion, S. Vizireanu, C. Luculescu, A. Cimpean, G. Dinescu. Journal of Physics D: Applied Physics, 2016, 49,17.

(9) P.Y. Tessier, R. Issaoui, E. Luais, M. Boujtita, A. Granier, B. Anglerau, Solid State Sciences, 2009, 11, 1824.

(10) M. Hiramatsu, M. Hori. Carbon Nanowalls, Synthesis and Emerging Applications, Springer Wien New York 2010.

(11) T. Labbaye, A. Canizarès, M. Gaillard, T. Lecas, E. Kovacevic, Ch. Boulmer-Leborgne, T. Strunskus, N. Raimboux, P. Simon, G. Guimbretière M. R. Ammar, Appl.Phys. Let. 2014, 105, 213109.