Immobilization of Laccase Nanoflower in Polydopamine Biofilm for Biocathode Formation and Its Integration with Glucose Dehydrogenase Bioanode in a Membrane-free of Glucose/O2 Biofuel Cell

In this research, a glucose/O2 biofuel cell was developed with glucose dehydrogenase bioande and laccase biocathode. Laccase nanoflowers were immobilized onto gold nanoparticles, which were electrodeposited on a gold electrode and polydopamine biofilm was employed to keep the immobilized laccase nanoflowers in place. The biocathode illustrated a high electrocatalytic activity toward oxygen reduction reaction with a direct electron transfer at a positive potential of +0.61 V (vs. Ag/ AgCl). For the preparation of a bioanode, glassy carbon electrode was modified in a layer by layer structure of graphene oxide nano-sheets, glucose dehydrogenase, and nicotine amide adenine dinucleotide by electrostatic affinities and the capping layer consist of glutaraldehyde, bovine serum albumin and glucose dehydrogenase. The proposed system depicted a high bioelectrocatalytic activity toward glucose oxidation and the oxidation commenced at -0.30 V (vs. Ag/ AgCl).