Determination of Organophosphorus Pesticides Based on Biotin-Avidin Enzyme Linked Immunosorbent Assay

A multienzyme system was generated by the specific reaction between biotin and avidin. Based on the system, a biotin-avidin amplified enzyme-linked immunosorbent assay ( BA-ELISA) method was developed and optimized for the determination of O,O-diethyl organophosphorus pesticides. Under the optimized experiment conditions, a good linear relationship between the concentrations of O, O-diethyl organophosphorus pesticides and inhibition ratio in the range of 0. 1-1. 0 X 10(4)mu g/L was obtained. The regression equation for the determination of diethylphosphonoacetic acid (DPA) was y=0. 1168 1gC(DPA) +0. 6259 (r = 0. 9889), 1050 and the detection limit were 34 and 0.0248 mu g/L, respectively. Compared with the ELISA, the sensitivity and detecting range were significantly improved while the cross-reaction remained unchanged. The recovery of the spiked samples was in the range from 70. 1% to 117. 8%, basically meeting the requirement of trace analysis. (O,O-diethyl organophosphorus pesticides.