Bioelectrocatalytic reduction of dioxygen to water at neutral pH using bilirubin oxidase as an enzyme and 2,2 '-azinobis (3-ethylbenzothiazolin-6-sulfonate) as an electron transfer mediator

Electrochemical reduction of dioxygen to water proceeds very effectively at 0.4 V versus Ag \ AgCl in pH 7.0 solution at an ambient temperature throug h the 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonate) (ABTS(2-))-mediate d and bilirubin oxidase (BOD) [EC 1.3.3.5]-catalyzed reaction of dioxygen. Electrochemistry of the ABTS(2-) oxidation and the indirect catalytic reduc tion of dioxygen with ABTS(2-) and BOD have been studied in detail to eluci date fully the bioelectrocatalytic behavior. The bioelectrocatalytic system using a carbon felt electrode has been examined and discussed in view of t he cathode reaction in a biofuel cell. (C) 2001 Elsevier Science B.V. All r ights reserved.