Mepiquat chloride (MQ) residues threaten human health and ecological safety, requiring rapid and sensitive monitoring. In this study, five haptens were designed for poorly immunogenic MQ, and MQ-H4/MQ-H5 was identified as the optimal pair via computer-aided analysis and serum validation, generating MQ mAb-5H2 with high affinity and specificity. Based on this mAb, a gold nanoparticle-based lateral-flow immunochromatographic assay was developed for MQ on-site screening, with the calculated limits of detection of 0.034, 0.049, and 0.016 mg/kg in potato, wheat, and soil, respectively. The reliability and accuracy of the method were verified through spiked recovery experiments, showing recoveries from 95.2 to 105.7% and a coefficient of variation of 1.6-7.1%, consistent with the results of high-performance liquid chromatography-mass spectrometry, providing a practical and reliable tool for MQ monitoring and a hapten-driven strategy for high-performance antibody generation and sensitive immunoassays targeting other quaternary ammonium pesticides.
Li et al. (Mon,) studied this question.