Computation-aided hapten design for highly specific monoclonal antibody and one-step immunochromatographic assay of indomethacin in food and environment.

Indomethacin (IDM) poses significant safety concerns due to its illegal addition to food and notable environmental persistence. Consequently, there is an urgent need to establish efficient and rapid detection methods applicable to both food and environmental samples. In this study, guided by the analysis and prediction of IDM's characteristic functional groups, a highly specific monoclonal antibody against IDM was generated, showing an IC50 value of 0.68 ng/mL and cross-reactivity rates below 1.30 % with structural analogues. The recognition mechanism of IDM was further elucidated using homology modeling and molecular docking. Based on the prepared antibodies, a rapid and reliable colloidal gold immunochromatography assay (CG-ICA) was developed, achieving a CCβ value as low as 6 ng/g, in compliance with the requirements of the China Administration for Market Regulation. In the analysis of 20 blind samples, the results of this method were fully consistent with those obtained by LC-MS/MS. Furthermore, the test strips remain stable at room temperature for up to 45 days. Therefore, the rapid detection method developed in this study was accurate and reliable, making it suitable for the key screening and monitoring of IDM in food and environmental samples.