Highly sensitive detection of tetracycline by electrochemical molecular imprinting

Tetracycline (TC) residue is an important food safety problem of animal origin at present, and the detection of tetracycline residue in food is of great significance to human health. In this work, nano-alumina (Al₂O₃) and graphene oxide (GO) were used as sensitizing materials. TC is used as a template molecule. Mesaminophenol (MAP) and β-cyclodextrin (β-CD) have been developed as a novel molecular imprinted (MIP) electrochemical sensor for the sensitive detection of TC as bi-functional monomers. The surface morphology and electrochemical performance of the imprinted sensor were characterized by scanning electron microscopy (SEM), differential pulse voltammetry (DPV) and electrochemical electrochemical impedance spectroscopy (EIS). At the same time, the influences of various parameters, such as the amount of GO and Al₂O₃ modification and the mole ratio of template molecule to functional monomer, on the response of MIP sensor were optimized. The results show that the prepared sensor has high selectivity and sensitivity to TC, due to the synergistic effect of Al₂O₃ and GO can significantly improve the surface area and catalytic performance of the modified electrode. Under the optimized conditions, the peak current of the sensor has a good linear relationship with the TC concentration in the range of 1.0–60.0 nM, and the detection limit is 0.16 nM. The proposed MIP sensor has been successfully applied to the determination of TC content in chicken feed and milk samples.