Detection of colistin (Polymyxin B) a restricted drug in chicken eggs using a label-free immunosensor based on Au screen-printed electrodes

This article highlights a label-free point-of-care detection of colistin (Polymyxin B) with modified immunosensor in chicken eggs. The manufacturing of screen-printed gold electrodes (Au-SPEs) is claimed to improve the sensor's sensitivity and point-of-care diagnostics, outperforming the outputs in terms of time and accuracy. The sensor attached a specific colistin antibody to a conventional Au-SPE that had been polyethyleneimine (PEI) modified by a carbodiimide-mediated amide coupling procedure. Using cyclic voltammetry (CV) and (K 3 Fe (CN) 6 ) − as a redox probe during each stage of fabrication, this immunosensor captured the electrochemical changes in the sample laced with colistin. Characterization of Au-SPEs was done with AFM for surface morphology and topographic data and FTIR for the functional group confirmation. Limit of Detection (LOD) of 1.539 µg/kg of egg with high specificity toward antigen against other antibiotics was observed. Therefore, the proposed immunosensor based on Au-SPEs has potential applicability for early detection of colistin which could be a promising tool for its rapid detection.