One-Step Platform for Maduramicin and Salinomycin Detection Based on Bispecific Monoclonal Antibody and Interpretation of Molecular Recognition Mechanism

Maduramicin (MAD) and salinomycin (SAL) are the widely used poly(ether ionophore) antibiotics to control coccidiosis in animals. Due to their strong cytotoxicity, strict control over their dosage and residue in animal food is necessary. To improve the detection efficiency of the existing single-residue detection methods, a tetraploid tumor hybrid system was constructed using drug mutagenesis, and the bispecific monoclonal antibody (BsMAb) against MAD and SAL was obtained by hybridization-hybridoma technology. By optimizing the optimal working concentration of the tracer and antibody, a multiresidue fluorescence polarization immunoassay method based on BsMAb was successfully established. The whole detection process takes 10 min, and the LOD values of MAD and SAL were 4.71 and 3.49 ng·g–1, respectively. IC50 values were 6.45 and 6.24 ng·mL–1, respectively. There was no cross-reactivity with other polyether ionophore antibiotics. Finally, a breakthrough in detection was achieved: bispecific monoclonal antibody prepared by the hybridization-hybridoma technology was used to detect maduramicin and salinomycin.