Substrate-bound tyrosinase electrode using gold nanoparticles anchored to pyrroloquinoline quinone for a pesticide biosensor

Enzyme electrodes hold great promise for on-line monitoring of environmental pollutants such as pesticides, but there has been a barrier to convenient use since they require substrate to activate or maintain enzyme activity. This work describes an approach for substrate integrating enzyme activation and corresponding current response at the substrate-bound enzyme electrode. Tyrosinase was activated by the use of reduced pyrroloquinoline quinone which was covalently bonded with the modified gold nanoparticles, the mechanism being identified with cyclic and differential pulse voltammetry. The sensitivity was enhanced by the use of gold nanoparticles and the tyrosinase activity was maintained and converted into current signals.