Immunodetection and Molecular Recognition Mechanism of Antibodies against Enrofloxacin

Enrofloxacin(ENR) is a veterinary drug with strongly toxic side effects in humans. Therefore, the detection of ENR in food has important implications for food safety. Anti-ENR monoclonal antibody(m AB) was prepared by immunizing BALB/c mice with conjugates of ENR and bovine serum albumin(BSA). The resulting monoclonal antibody was used to establish a direct competitive enzyme-linked immunoabsorbent assay(ELISA) to detect ENR in goat milk samples. The limit of the detection(IC15) was 0.04 ± 0.02 ng/m L and half inhibition rate(IC50) was 0.71 ± 0.05 ng/m L. The recovery rates were 96.56% to 105.10% when ENR concentrations were between 10 and 200 ng/m L in goat milk. ELISA and high-pressure liquid chromatography(HPLC) showed a good linear correlation(R2=0.9998). Finally, the 3-dimentional(3D) structure of the ENR antibody variable region was modelled and docked using computer bioinformatics. The results showed that Arg98, Asp99, Gly101, Thr50, Ser51, Ala82, and Tyr85 performed key functions during antibody-antigen recognition. The results of this study provide theoretical guidance for future antibody structure modifications.