Development of a monoclonal antibody-based indirect competitive chemiluminescence immunoassay for nitrofurantoin metabolite AHD residue in fish samples

An ultrasensitive indirect competitive chemiluminescence immunoassay (icCLEIA) based on monoclonal antibodies (mAb) for the effective detection of nitrofurantoin metabolite 1-aminohydantoin was developed under optimal conditions in our study. 1-aminohydantoin (AHD) was derivatized with m-formylphenoxyacetic acid (MCEP) to obtain a hapten MCEPAHD. The developed icCLEIA based on anti-MCEPAHD mAb showed high sensitivity to competing drugs 2-nitrophenyl derivative of AHD (2NPAHD) with a limit of detection (LOD) 0.04 ng/mL and a 50 % inhibitory concentration (IC 50 ) 0.27 ng/mL, and the icCLEIA had an ultra-high specificity for 2NPAHD, with little cross-reactivity with structural analogues other than parent drug nitrofurantoin. The mean recovery of AHD in fish samples was found to be 97.0 % to 118.5 %, with a coefficient of variation of less than 7.0 %. A comparison of the results of ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) with those of icCLEIA demonstrated good linearity. These assay results indicated that the prepared mAb against MCEPAHD and the developed icCLEIA in our research can be used for simple, fast and sensitive detection of AHD residues in animal tissues.