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 x 10(-8) M to 5 x 10(-5) M, a lower detection limit of 3 x 10(-8) M, a current maximum (I-max) of 65.8 mu A and an apparent Michaelis constant (K-m(app)) of 169.9 mu M. (C) 2018 Elsevier B.V. All rights reserved.