Click chemistry-assisted hapten modification for enhanced immunoassay development: A promising strategy for clodinafop-propargyl detection in environmental and food samples.

Clodinafop-propargyl (CP), a WHO Class III toxic herbicide, poses significant public health and environmental risks. This study presents a click chemistry-based hapten modification strategy to develop highly specific monoclonal antibody (mAb) for ultrasensitive CP immunoassay. Compared to conventional hapten synthesis methods, the click chemistry-derived hapten exhibited superior performance in indirect competitive ELISA (ic-ELISA), achieving a detection limit (LOD) of 5.6 pg mL-1, an IC50 of 171.4 pg mL-1, and a broad dynamic range (IC20-IC80: 12.8 pg mL-1-2.3 ng mL-1). The assay demonstrated high accuracy in detecting CP residues across water, soil, wheat, and meat samples, with intra- and inter-assay recoveries of 76.5-106.5 % and 75.5-109.5 %, respectively. Validation via HPLC-UV showed recoveries of 77.9-98.5 %, confirming method reliability. This approach highlights click chemistry as a robust tool for hapten design, enabling cost-effective, high-throughput, and ultrasensitive CP monitoring in environmental and food safety applications.