Enzymatic carbon nanotube based composite electrodes for dioxygen reduction
|Katarzyna A. Karnicka , Przemysław Ziaja , Krzysztof Miecznikowski , Paweł J. Kulesza|
Warsaw University, Faculty of Chemistry, Pasteura 1, Warszawa 02-093, Poland
One of the most frequently considered enzymes for use as the cathodic biocatalyst in biofuel cells is laccase. It belongs to the multi-copper group of oxidases, and drives the four-electron reduction of the co-substrate O2 to H2O effectively, while it is quite unspecific with respect to the electron donating substrate. The dianion ABTS2- (2,2’ – Azinobis (3 – ethylbenzothiazoline – 6 – sulfonate)) undergoes a reversible oxidation - reduction reaction and is commonly used with oxygen reducing enzymes as a mediator. ABTS was mostly considered as a diffusional mediator but recently attempts have been made to immobilize ABTS together with laccase on the electrode surface. In order to improve the effectiveness of the bio-electrocatalytic system for the electro-reduction of oxygen, we have employed carbon nanotubes (CNTs). Carbon nanotubes exhibit very good mechanical and electronic properties and they facilitate electron transfer in bioelectrocatalytic systems. We have prepared colloidal suspensions of carbon nanotubes modified with ABTS utilizing the procedure proposed by us for the fabrication of phosphomolybdate-stabilized carbon nanotubes . The bioelectrocatalytic film based on CNTs_ABTS and laccase exhibits very good electrocatalytic activity towards oxygen reduction. The combination of CNTs and ABTS gives a highly effective mediation system able to propagate charge between the active center of the enzyme and the electrode surface.
 P.J. Kulesza, M. Skunik, B. Baranowska, K. Miecznikowski, M. Chojak, K. Karnicka, E. Frackowiak, F. Beguin, A. Kuhn, M. –H. Delville, B. Starobrzyńska, A. Ernst, Electrochim. Acta 51(2006)2373
Presentation: Poster at SMCBS'2007 International Workshop, by Katarzyna A. Karnicka
See On-line Journal of SMCBS'2007 International Workshop
Submitted: 2007-09-07 14:27 Revised: 2009-06-07 00:44