Development of a lateral flow immunoassay for the on-site detection of Acifluorfen in agricultural products

Acifluorfen (AFF), a widely used diphenyl ether herbicide, raises significant environmental concerns due to its persistence and ecotoxicological risks, but the absence of immunoassay methods hinder efficient monitoring. A hybridoma cell line secreting a monoclonal antibody against AFF was developed via hybridoma technology to address this need. Using this antibody, we developed two lateral flow immunoassays (LFIAs) based on gold nanoparticles (AuNP-LFIA) and gold nanoflowers (AuNF-LFIA). The AuNP-LFIA exhibited a limit of detection (LOD) of 75.01 ng/mL. In contrast, the AuNF-LFIA demonstrated significantly enhanced sensitivity, achieving an LOD as low as 7.79 ng/mL, which represents a 9.6-fold improvement over the AuNP-LFIA. When applied to fruit and vegetable samples, both methods showed spike recovery rates ranging from 92.58% to 108.41%, and the results were in good agreement with those obtained by LC-MS. These findings suggest that the developed assays hold strong potential as reliable tools for the on-site detection of AFF. • We report the first development of monoclonal antibodies specifically targeting acifluorfen, thereby addressing a critical gap in the immunodetection tools available for this herbicide. • Ultrasensitive and specific detection achieved using a gold nanoflower-based lateral flow immunoassay, with a detection limit of 7.79 ng/mL and no cross-reactivity with common analogues. • Proven reliability in spiked agricultural samples, demonstrating the method's strong potential for rapid, on-site monitoring of AFF residues to enhance food safety control.