Electrochemical characterization of adsorbed bilirubin oxidase on Vulcan XC 72R for the biocathode preparation in a glucose/O2 biofuel cell

A new biocathode was built and tested. It consisted of bilirubin oxidase adsorbed on Vulcan XC 72 R and immobilized into a Nafion® matrix. The possibility of direct electron transfer between bilirubin oxidase and Vulcan XC 72 R was also demonstrated. The kinetics on biocathode were enhanced by including 2,2′-azinobis-3-ethylbenzothiazoline-5-sulfonic acid in the catalytic film. A first order reaction rate was observed for oxygen concentrations lower than 22%. A complete kinetic investigation of the system was shown. A biofuel cell test performed with this biocathode and Au70Pt30 nanoparticles as anode catalyst permitted to reach a power density of 170 μW cm−2 at a cell voltage of 0.6 V, which is superior to what can be obtained with the concentric design.