A rabbit monoclonal antibody-based sensitive competitive indirect enzyme-linked immunoassay for rapid detection of chloramphenicol residue

A sensitive competitive indirect enzyme-linked immunoassay (ciELISA) based on a rabbit monoclonal antibody (RabMAb) against chloramphenicol (CAP) has been developed and validated in this study. After optimisation of several key physico-chemical factors, such as Tween-20 percentage, pH value and ionic strength, the immunoassay showed excellent performance within the linear range of 0.18-6.37 ng mL(-1), with the 50% inhibition concentration (IC50) of 1.06 ng mL(-1) and the limit of detection (LOD) of 0.1 ng mL(-1). In addition, the cross-reactivities of RabMAb towards chloramphenicol succinate, florfenicol and thiamphenicol were 2.09, 12.45 and 18.10%, respectively. Finally, the developed method was applied in spiked swine urine, milk and honey samples, with recoveries ranging from 71.03 to 109.62%. The result demonstrated that the developed immunoassay is a valuable method for screening and quantitation of CAP residues in real samples.