Establishment of a lateral flow colloidal gold immunoassay strip for the rapid detection of estradiol in milk samples

•A panel of monoclonal antibodies (mAb) specific for estradiol (E2) screening was produced.•A lateral flow colloidal gold immunoassay strip for determining E2 in milk samples was established with the E2 mAb.•The strip in this study could be used to detect the E2 residue within the range of 37.14-1484.65 pg/mL in prepared milk samples.

It is a fact that the level of estradiol (E2) in powdered milk has been increased manyfold with growing concerns on dairy safety. Our study produced a panel of monoclonal antibodies (mAb) specific for E2 screening and established a lateral flow colloidal gold immunoassay strip for determining E2 in milk samples with the E2 mAb. The sensitivity of the test strip was found to be 180.42 ± 3.17 pg/mL and the lower detection limit (LDL) value was 37.14 pg/mL. For negative milk samples spiked with 400, 800, and 1200 pg/mL, the recovery range was 86.7-93.5% and the coefficient of variation scope [CV (%)] was 4.8-6.2%. The results of comparative studies between test strips and HPLC were relatively identical while the strip test only required less than 8 min. In the study, the test strip was a practical screening technology for quantitative, semi-quantitative, or qualitative detection of E2 residues.