Development of an ic-ELISA and immunochromatographic assay strip for the rapid detection of chloridazon in oranges and celery.

Chloridazon (CLZ) is a selective herbicide used in the control of annual broadleaf weeds. The misuse or abuse of CLZ may result in the accumulation of CLZ in crops and water, which can pose a risk to human health. In this study, a hapten of CLZ with three carbon spacer arms was designed and a highly sensitive and specific antibody against CLZ was prepared with a half-maximal inhibitory concentration of 0.630 ng mL -1 and a linear range of 0.181-2.195 ng mL -1 .Based on this antibody, we developed an immunochromatographic assay (ICA) strip for the detection of CLZ in oranges and celery. Under optimized conditions, the visual limit of detection was 2 ng mL -1 and 10 ng mL -1 in oranges and celery, respectively, and the cut-off value was 50 ng mL -1 . In CLZ-spiked samples and the recovery test, the results of the ICA strip were consistent with those of indirect competitive enzyme-linked immunosorbent assay (ic-ELISA). Therefore, the ICA strip developed in our study represents an efficient and reliable method for the rapid screening of CLZ in oranges and celery.