Lateral flow immunochromatographic assay based on computational chemistry-assisted hapten screening for the detection of ethoxyquin in food samples

Ethoxyquin (EQ), widely used as a potent antioxidant in intensive agricultural, requires reliable analytical methods for rapid detection due to its toxicological risks and potential for widespread contamination. In this study, computer-assisted molecular simulations were utilized to screen for a novel hapten through conformational studies and electronic analyses. Monoclonal antibodies against EQ were prepared using hybridoma technology, exhibiting a half-maximal inhibitory concentration of 9.54 ng/mL. A gold nanoparticles-based lateral flow immunochromatographic assay (LFIA) was established for the analysis of EQ in apples, pears, and fish meat, with quantitative detection ranges of 0.03–0.42 mg/kg, 0.03–0.70 mg/kg, and 0.04–0.93 mg/kg, respectively. The spiking recoveries of LFIA for real samples ranged from 88.63 % to 106.90 %, with RSDs between 2.24 % and 7.93 %. These results align with the instrumental method, indicating that this immunoassay can accurately and efficiently detect EQ residues in foodstuffs in resource-limited areas.