A highly sensitive electrochemical biosensor for phenol derivatives using a graphene oxide-modified tyrosinase electrode

The fabrication, characterization and analytical performance were investigated for a phenol biosensor based on the covalent bonding of tyrosinase (TYR) onto a graphene oxide (GO)-modified glassy carbon electrode (GCE) via glutaraldehyde (GA). The surface morphology of the modified electrode was studied by atomic force microscope (AFM) and field-emission scanning electron microscopy (FE-SEM). The fabricated TYR/GA/GO/GCE biosensor showed very good stability, reproducibility, sensitivity and practical usage. The catechol biosensor exhibited a wide sensing linear range from 5×10−8M to 5×10−5M, a lower detection limit of 3×10−8M, a current maximum (Imax) of 65.8μA and an apparent Michaelis constant (Kmapp) of 169.9μM. Schematic illustration of the TYR/GA/GO/GCE biosensor for electrochemical determination of phenol derivatives. [Display omitted] •It is a novel research by using covalent bonding between graphene oxide and tyrosinase instead of physical adsorption.•The OH group was utilized for covalent bonding.•The fabrication conditions were investigated and optimized.•The method provides a wider choice for constructing phenol biosensors.