Direct electrochemistry and electrocatalysis of immobilised cytochrome c on electrodeposited nanoparticles for the reduction of oxygen

Direct electrochemical response of cytochrome c (cyt c) on the modified electrode was studied by cyclic voltammetry. The results indicated that cyt c could be adsorbed on the surface of the electrodeposited cobalt oxyhydroxide nanoparticles (CoOx NPs) modified electrode. A couple of well-defined redox peaks can be observed in a phosphate buffer solution (pH 7.0), whose formal potential, E°´ (defined as the average of reductive and oxidative peaks), was -86.5 mV with respect to the reference electrode equal to 110.5 mV against normal hydrogen electrode. Cyt c adsorbed on the surface of CoOx NPs shows a remarkable electrocatalytic activity for the reduction of oxygen. Based on these, a third-generation biosensor could be developed to detect the concentration of oxygen in aqueous solution.