Broad-specificity and ultrasensitive immunochromatographic detection of bentazone and its metabolites using computer-aided hapten screening.

Bentazone (Ben) is a benzothiadiazole herbicide, and its widespread use can lead to excessive residues in crop products, polluting environmental water and soil. Ben and its metabolites 6-hydroxybentazone, 8-hydroxybentazone, and Bentazone methyl are all toxic to human, therefore it's crucial to detect Ben and metabolites. In this study, the epitope information of Ben was analyzed from molecular space conformation and electrostatic potential distribution. Three novel haptens were prepared by designing and modifying the benzene ring, imine, and carbonyl groups of Ben molecule. The matrix effect enhancement screening method was used to obtain high affinity and broad-spectrum monoclonal antibodies (mAbs). The co-monitoring of Ben and its metabolites could be realized at one time, different from other detection methods. The IC50 values of mAbs against Ben was 1.70 ng/mL. The colloidal gold immunochromatography was firstly developed to detect Ben in lake water, soil, and French bean samples with LOD of 1.47 ng/g, 1.54 ng/g, and 4.83 ng/g, respectively, and detection ranges of 2.52-22.71 ng/g, 2.64-139.73 ng/g, and 8.31-49.36 ng/g, respectively. The recovery rate was 88.5 %-99.5 %, and confirmed by positive Ben samples. The CGIA exhibited excellent detection performance for on-site detection of Ben and metabolites in environmental samples.