Epitope imprinted electrochemical sensor for highly sensitive detection of alpha-fetoprotein

A selective and sensitive epitope imprinted electrochemical sensor for the precise quantification of alpha-fetoprotein (AFP) was developed through electropolymerization by using the C-terminus of alpha-fetoprotein as the template and o-phenylenediamine as the functional monomer. The prepared epitope molecularly imprinted polymer film was characterized by the scanning electron microscope (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Experimental parameters including the molar ratio of template to functional monomer, electropolymerization cycle, elution time and rebinding time were systemically investigated and optimized. Under optimized conditions, the proposed epitope imprinted electrochemical sensor demonstrated outstanding sensing capabilities within the alpha-fetoprotein concentration range of 0.1 pg mL−1 to 1.0 μg mL−1, with a limit of detection of 0.075 pg mL−1. Furthermore, this electrochemical sensor exhibited exceptional selectivity when tested against other proteins or disease biomarkers, including human serum albumin, bovine serum albumin, prostate-specific antigen and carcinoembryonic antigen. In practical application, it was successfully employed for the analysis of alpha-fetoprotein in human serum samples, yielding a recovery rate ranging from 99.70 % to 108.48 %. This study proposed a straightforward approach for the construction of epitope molecularly imprinted electrochemical sensor tailored for the determination of alpha-fetoprotein.