Development of an indirect competitive enzyme-linked immunosorbent assay for propiconazole based on monoclonal antibody

Propiconazole is a widely used fungicide in agricultural production, but it poses risks to human health. Here, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) based on a monoclonal antibody (mAb) was established to detect propiconazole residues. Three haptens of propiconazole were designed and synthesized to prepare antigens. Ten mAbs were obtained using hapten B (5-(4-(2-((1H-1,2,4-triazol-1-yl)methyl)-4-propyl-1,3-dioxolan-2-yl)-3-chlorophenyl) pentanoic acid). The ic-ELISA based on the combination of mAb 2G2E12 and hapten B-ovalbumin (coating antigen) showed the highest sensitivity. After optimization, the 50% inhibition concentration, limit of detection and linear range of the ic-ELISA were 2.33 μg/L, 0.26 μg/L and 0.26–21.28 μg/L, respectively. The cross-reactivities for the analogs of propiconazole were ≤1.9%. The average recoveries of the spiked samples were 75.7%–117.0% with relative standard deviations of ≤9.4%. The results of the ic-ELISA were consistent with those of gas chromatography-mass spectrometry in the analysis of blind samples. Therefore, we provide an alternative tool for the accurate and reliable determination of propiconazole.