Substrate-bound Tyrosinase Electrode 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 manuscript describes an approach for substrate integrating enzyme activation and corresponding current response at the substrate-bound enzyme electrode. Tyrosinase (TYR) was activated by the use of reduced pyrroloquinoline quinine (PQQ) which was covalently bonded with the functionalized self-assembled monolayer (SAM) modified gold nanoparticles, the mechanism being identified with cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The sensitivity was enhanced by the use of gold nanoparticles and the tyrosinase activity was maintained and converted into current signals.