A label-free impedimetric immunosensor for detection of 1-aminohydantoin residue in food samples based on sol–gel embedding antibody

A novel label-free impedimetric immunosensor for detection 1-aminohydantoin (AHD) was first constructed by the silica sol–gel immobilization of monoclonal antibody against 1-aminohydantoin antibody (AHD-McAb) on the surface of glassy carbon electrode (GCE). The electrochemical impedance spectroscopy of ferricyanide was used as a marker to probe the interface and as a redox probe to determinate AHD. The effect of operational parameters, such as amount of immobilized AHD-McAb, pH, incubation time, and incubation temperature, has been explored for the optimum analytical performance of the impedimetric immunosensor. Under the optimized conditions, the change in impedance was proportional to AHD concentrations in the range of 2.0–1.0 × 103 ng/mL (r = 0.9990) with the detection limit of 2.0 ng/mL. The specificity, reproducibility, stability, and accuracy of the proposed impedimetric immunosensor were also evaluated. In addition, the proposed immunosensor was successfully applied for the determination of AHD in food samples using the standard adding method with recoveries of 93.7–104.9%. The results obtained by the proposed immunosensor corroborate very well with the method of HPLC–MS/MS for the determination of AHD in food samples.