Monoclonal antibody for the development of specific immunoassays to detect Enrofloxacin in foods of animal origin

The carbodiimide active ester method was employed to synthesise the antigen of 1-cyclopropyl-7-(4-ethylpiperazin-1-yl)-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid [Enrofloxacin (ENFX)], and male Balb/c mice were used to produce anti-ENFX monoclonal antibody. Based on the checkerboard titration, an indirect competitive enzyme-linked immunosorbent assay standard curve was established. This assay was sensitive and highly specific to ENFX with the half maximal inhibitory concentration and limit of detection values of 0.15 ng mL⁻¹ and 0.028ng mL⁻¹, respectively. Similarly, the antibody had a high affinity as seen in A _max values. Spiked cow milk beef liver and fish samples analysed using this kit had recoveries in the range of 90.2–110.2%, 70.7–81.5% and 89.1–101%, respectively, showing satisfactory results. The results suggest that this ELISA kit could be applied as a screening method to detect and control the illegal content of ENFX in food products.