Localized Electrochemistry and Controlled Modifications of Surfaces. Seminar

Philippe Hapiot - Localized Electrochemistry and Controlled Modifications of Surfaces.

For the last twenty years, there has been a large development of surface functionalization toward surfaces exhibiting remarkable physical and chemical properties. More recently, one could observe the explosion of research efforts based on several physical and chemical deposition techniques to generate micro and now nano-structured surfaces or surfaces supporting nano-objects like nanoparticles or dendrimers. These efforts are supported by the large range of possible applications as for example those in analytical, bio-analytical chemistry or molecular electronic. In relation with these expending fields, classical electrochemistry and the more recent developments of electrochemistry at a local scale (micro- and nano-electrochemistry) appear as versatile and straightforward means for building and analyzing functionalized and nanostructured surfaces.

In this lecture, the developments of a global electrochemical strategy for preparing versatile and robust reactive platforms will be presented. Such molecular platforms could be used for immobilizing active molecules onto different substrates especially on carbon materials.[1,2] These strategies are based on the electro-grafting of electro-generated aryl radicals [3] followed by a post-functionalization of the first grafted layer, allowing us to preserve the activity of fragile immobilized groups.[1-4] This approach could be extended to the controlled design of multifunctional films (a film containing at least two functional groups) that are covalently bonded to the surface.

In a second part of the lecture, we will discuss how the surface reaction properties of the functionalized surface could be probed through electrochemical techniques, Scanning Electrochemical Microscopy (SECM) being particularly well adapted. SECM also permits reversible or irreversible patterning of the layer. Different examples of such modified surfaces and of their applications will be presented, notably recent results in relation with the study of surface reactions implying reactive oxygen species.[4-6]



REFERENCES
[1] Leroux, Y. R.; Fei, H.; Noël, J.-M.; Roux, C.; Hapiot, P. J. Am. Chem. Soc. 2010, 132, 14039.
[2] Cremer, P.S. J. Am. Chem. Soc. (Editorial) 2011, 133, 167.
[3] Pinson, J.; Podvorica, F. Chem. Soc. Rev. 2005, 34, 429.
[4] Zigah, D.; Noel, J.-M.; Lagrost, C.; Hapiot, P. J. Phys. Chem. C 2010, 114, 3075.
[5] Wang, A.; Ornelas, C.; Astruc, D.; Hapiot, P. J. Am. Chem. Soc. 2009, 131, 6652.
[6] J.-M. Noël, A. Latus, C. Lagrost, E. Volanschi, P.Hapiot, J. Am. Chem. Soc. 2012, 134, 2835–2841