Development of fluorescence polarization immunoassay for the detection of organophosphorus pesticides parathion and azinphos-methyl.

Organophosphorus Pesticides (OPPs) are a group of artificially synthesized substances used in farms to control pests and to enhance agricultural production. Although these compounds show preferential toxicity to insects, they are also toxic to humans and mammals by the same mode of action. ELISA now is an alternative method to detect OPPs. But, it must bear heterogenous properties, since several separation steps are needed during the ELISA method protocols. The FPIAs, which belong to homogenous assay, for determination of OPPs parathion and zainphos-methyl have been developed. The characteristics of Dep-EDF and PM-B-EDF tracers binding with antibodies A and D were investigated in the antibodies dilution experiments. The PM-B-EDF tracer combination with antibody D was selected to construct the standard curve for parathion detection. The IC50 value and the detection of limit were 1.96 mg/L and 0.179 mg/L, respectively, as shown in the standard curve. The tracers of PBM-EDF 2 and 3, which were chased from 4 PBM-EDF tracers, exhibited the good standard curves based on the MAb AZI-110. The FPIA constructed to analyze the azinphos-methyl showed the IC50 1.003 mg/L and detection limit 0.955 mg/L when PBM-EDF 2 was employed and the IC50 0.1487 mg/L and detection limit 0.150 mg/L were obtained when PBM-EDF 3 was used.