Development of a lateral flow immunoassay for the rapid detection of diclofenac in milk and milk tea.

Diclofenac (DCF) is widely used in veterinary medicine, but its milk residues may pose risks to human health. This study designed DCF haptens using computer modeling and developed an anti-DCF monoclonal antibody (mAb) with milk samples, achieving a semi-inhibitory concentration of 0.379 ng/mL. A lateral flow immunoassay (LFIA) was created to detect DCF residues in milk and milk tea, with calculated limits of detection (cLOD) of 0.083 ng/mL for milk and 0.055 ng/mL for milk tea. The results obtained from the LFIA assay for real samples, as well as the recovery rates, were consistent with those obtained from instrumental methods. Notably, the LOD for milk using this method was at least one order of magnitude higher than that of other methods. The method shows promise for detecting DCF in real milk and milk tea.