Development of a sensitive indirect competitive enzyme-linked immunosorbent assay based on the monoclonal antibody for the detection of benzothiostrobin residue

Abstract

An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) based on monoclonal antibodies (MAbs) for benzothiostrobin has been developed. The hapten of benzothiostrobin was synthesized and conjugated to bovine serum albumin and ovalbumin to generate an immunogen and a coating antigen. The immunogen was used to immunize BALB/c mice, resulting in anti-benzothiostrobin MAb. Under optimal conditions, the half maximal inhibition concentration (IC₅₀) and the limit of detection (IC₁₀) of the developed ic-ELISA were 7.55 and 0.428 μg L⁻¹, respectively. The cross-reactivity (CR) was less than 0.05% for the tested structural analogues and regarded as negligible except for pyraclostrobin, which exhibited a CR of 0.34%. The recoveries of benzothiostrobin ranged from 80.43 to 113.83% in environmental and agricultural samples, respectively, which conformed to the requirements for residue detection. The amount of benzothiostrobin detected by ic-ELISA in the samples was significantly (R² = 0.9894, y = 1.0867x + 0.0318) correlated with that detected by high-performance liquid chromatography (HPLC). The current study indicates that the established ic-ELISA is a potentially useful tool for detecting benzothiostrobin in environmental and agricultural samples.