Development of Redox Polymer Grafted onto Carbon Black Using 2,2′-Azinobis(3-ethylbenzothiazoline-6-sulfonic Acid) as a Biocathode

Abstract

We immobilized 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate) through a spacer to polymer grafted onto carbon black to fabricate a three-dimensional biocathode with high surface area that reduces oxygen in the presence of laccase. Cyclic voltammetry using a rotating disk electrode shows that an oxygen reduction reaction (ORR) current density greater than 1 mA cm⁻² at 200 rpm was obtained using the grafted redox polymer in the presence of 1.0 mg mL⁻¹ of laccase in solution. The onset potential of the ORR current suggests that the electron transfer from carbon through grafted redox polymer to laccase was more effective than that through cast linear redox polymer.