Biofuel‐Cell Cathodes Based on Bilirubin Oxidase Immobilized through Organic Linkers on 3D Hierarchically Structured Carbon Electrodes

Abstract

Abstract Different modification procedures to stabilize and control the orientation of Myrothecium verrucaria bilirubin oxidase ( Mv BOD) on 3D carbon nanotube/carbon microfiber‐modified graphite electrode surfaces were evaluated for the development of biofuel‐cell cathodes. The surface properties of different linkers for covalent binding of BOD were investigated by using atomic force microscopy‐based techniques. For all immobilization strategies, the maximal current response was obtained at a pH value of 6.5 with temperatures between 20 and 35 °C. The biocathode based on Mv BOD immobilized through an imino bond to the electrode showed the highest current density (1600 μA cm −2 ) and was resistant to the presence of chloride ions. A biofuel cell was constructed, and it exhibited a maximal power of 54 μW cm −2 at 350 mV with an open‐circuit voltage of about 600 mV by using a cellobiose dehydrogenase based bioanode and glucose as the fuel.