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.

Layer-by-layer assembly of a redox enzyme displayed on the surface of elongated bacteria into a hierarchical artificial biofilm based anode.

To achieve an efficient electron transfer communication between bacteria and electrodes, several strategies including enzyme surface display, bacteria elongation as well as layer-by-layer assembly techniques were used to assemble bacteria, methylene blue, multiwall carbon nanotubes, and carbon papers into hierarchical micro/nano artificial biofilm based bioanodes.