Development of a versatile organophosphorous-hydrolase-based assay for organophosphate pesticides

摘要

Abstract: We report a rapid and versatile organophosphorus hydrolase (OPH)-based method for measurement of organophosphate pesticides. This assay is based on a substrate-dependant change in pH near the active site of the enzyme. The pH change is monitored using fluorescein isothiocyanate (FITC) which is covalently immobilized to the enzyme. This method employs FITC-labeled enzyme adsorbed to polymethylmethacrylate beads. Analytes were measured using a microbead fluorescence analyzer. The dynamic concentration range for the assay extends from 25 $mu@M to 400 $mu@M for paraoxon with a detection limit of 8 $mu@M. This assay compared favorably to an HPLC method for monitoring the concentration of coumaphos in bioremediation filtrate samples. !20