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

A multienzyme system was generated via a 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 in this study. Under the optimized experiment condition, a good linear relationship between inhibition ratio and O,O-diethyl organophosphorus pesticides in the range of 1 × 10−1-1 × 104 μg L−1 was obtained. The regression equation was y = 0.1168x + 0.6259 (r = 0.9889); IC50 and the detection limit were 34 and 0.0248 μg L−1, respectively. Compared with the traditional ELISA, the sensitivity and detecting range were significantly improved, although the cross-reaction remained unchanged. The recovery of the spiked samples was in the range of 70.1%-117.8%, basically meeting the requirement of trace analysis.