Rapid detection of four organophosphorous and neonicotinoid toxicants using bi-enzyme tracer competitive enzyme-linked immunosorbent assay.

摘要

A bi-enzyme tracer direct competitive enzyme-linked immunosorbent assay (dc-ELISA) based on two generic antibodies was developed. The effects of several physicochemical factors, such as heterologous antigen-horseradish peroxidase (HRP), methanol concentration, ionic strength, and pH value, were optimized to obtain satisfactory sensitivity of the assay. Under the optimized conditions, the 50 % inhibition concentration (IC₅₀) value for parathion, parathion-methyl, imidaclothiz, and imidacloprid was 57.28 +or- 2.73, 169.82 +or- 5.64, 52.48 +or- 3.46, and 53.08 +or- 2.05 mug L-1, with a limit of detection (LOD, IC₁₀) of 0.56, 3.16, 0.62, and 0.51 mug L-1, respectively. There was no obvious cross-reactivity (CR) with most of the neonicotinoids and organophosphorus pesticides. The recoveries of parathion, parathion-methyl, imidaclothiz, and imidacloprid in environmental and agricultural samples, including river water, soil, and cabbage, ranged from 82.54 to 116.29 %. The relative standard deviation (RSD) ranged from 1.59 to 8.09 %. The ELISA results were confirmed by gas chromatography (GC) with a high correlation coefficient of 0.9882. These results showed that the bi-enzyme tracer competitive enzyme-linked immunosorbent assay could be used as a sensitive tool for monitoring parathion, parathion-methyl, imidaclothiz, and imidacloprid in environmental samples and agricultural products. copyright Springer Science+Business Media New York 2013.