Enhancement of the Direct Electron Transfer-type Bioelectrocatalysis of Bilirubin Oxidase at the Interface between Carbon Particles

Abstract

The simulation model of the direct electron transfer (DET)-type bioelectrocatalysis at a porous electrode indicates that the catalytic current is proportional to the real surface area (A), when A is small. When A is large, the catalytic current is saturated at a limited value controlled by the mass transfer in the porous structure. In this study, the bioelectrocatalytic currents at porous electrodes are analyzed based on their charging currents. Comparisons among the carbon composites constructed with Vulcan and exfoliated graphite (JSP) show that the interface between the Vulcan and JSP particles is more suitable for the DET-type bioelectrocatalysis of bilirubin oxidase (BOD) than that between the particles of the same type. In particular, the most suitable properties were achieved at a Vulcan : JSP ratio of 1 : 1 in the composite electrode. In these composites, the multipoint contact between the BOD molecule and electrode seems to result in a higher DET-type bioelectrocatalytic activity.

Keywords

• bioelectrocatalysis
• carbon nanostructures
• direct electron transfer
• effective surface area