Biocomposite Based on Reduced Graphene Oxide Film Modified with Phenothiazone and Flavin Adenine Dinucleotide-Dependent Glucose Dehydrogenase for Glucose Sensing and Biofuel Cell Applications

A novel composite material for the encapsulation of redox enzymes was prepared. Reduced graphene oxide film with adsorbed phenothiazone was used as a highly efficient composite for electron transfer between flavin adenine dinucleotide (FAD)-dependent glucose dehydrogenase and electrodes. Measured redox potential for glucose oxidation was lower than 0 V vs Ag/AgCl electrode. The fabricated biosensor showed high sensitivity of 42 mA M^-1 cm^-2, a linear range of glucose detection of 0.5-12 mM, and good reproducibility and stability as well as high selectivity for different interfering compounds. In a semibiofuel cell configuration, the hybrid film generated high power output of 345 μW cm^-2. These results demonstrate a promising potential for this composition in various bioelectronic applications.