Enzyme-linked immunosorbent assay based on a monoclonal antibody for the detection of the insecticide triazophos: assay optimization and application to environmental samples.

A direct competitive enzyme-linked immunosorbent assay (ELISA) for triazophos was developed, which was based on the THHe monoclonal antibody (McAb) and a heterologous enzyme tracer (THBu-HRP). The influence of several physicochemical factors (temperature, time, pH, salt, detergent, and solvent) on the immunoassay was studied. For the standard curve, an I50 of 0.21 microg/L and a limit of detection (I20) of 0.02 microg/L was obtained in a high salt concentration buffer (0.05 M PBS, pH 6.0) with 0.05% BSA, which means an almost 3-fold improvement in the assay sensitivity in comparison with the nonoptimized conditions. The optimized ELISA has been used to quantify triazophos in water and soil samples spiked at different amounts. The excellent recoveries achieved confirmed the potential of the immunoassay for environmental monitoring of triazophos in waters and soils without purification steps.