Reversible electrochemistry of cytochrome c on recompressed, binderless exfoliated graphite electrodes

Rikhie, J and Sampath, S (2005) Reversible electrochemistry of cytochrome c on recompressed, binderless exfoliated graphite electrodes. In: Electroanalysis, 17 (9). pp. 762-768.

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Abstract

The direct electrochemistry of cytochrome c (cyt-c) has been investigated on exfoliated graphite (EG) electrodes. The as-polished and roughened (using SiC emery sheet) EG surfaces are inactive for the direct electron transfer. However, when the EG electrode was sonicated before the experiment, a pair of redox waves were obtained for freely diffusing cyt-c in the solution phase. The formal potential was found to be 0.01 V (vs. SCE) in 0.1 M phosphate buffer at a pH of 7.1. The electrochemical response for the adsorbed cyt-c on sonicated EG electrodes, which is shown to have carbonyl functional groups on its surface, shows nearly reversible voltammograms in the same electrolyte. However, the formal potential in the adsorbed state is more negative than that observed for the solution phase cyt-c. A structure based on an open heme conformation proposed by Hildebrandt and Stockburger is probably present on the EG surface. It is suggested that the electrochemistry at the EG electrode is essentially governed by favourable electrostatic interactions.

Item Type:	Journal Article
Publication:	Electroanalysis
Publisher:	John Wiley and Sons
Additional Information:	Copyright of this article belongs to John Wiley and Sons.
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	29 Apr 2010 05:23
Last Modified:	19 Sep 2010 06:00
URI:	http://eprints.iisc.ac.in/id/eprint/27371

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