Molecularly imprinted polypyrrole for the electrochemical detection of sulfadimethoxine: The effect of imprinting parameters

A novel, simple and cost-effective electrochemical sensor for sulfadimethoxine (SDM) based on molecularly imprinted overoxidized polypyrrole (PPy) is developed by exploiting an all electrochemical approach both for sensor fabrication and application consisting in molecularly imprinted polymer (MIP) electropolymerization/overoxidation and in SDM amperometric detection. Parameters influencing the imprinting effect are critically evaluated. A key role of the electrolyte used in electropolymerization is demonstrated to influence MIP sensing performances and its morphology, as highlighted by atomic force microscopy (AFM). MIP-template interaction is verified by IR spectroscopy. The effect of different overoxidation conditions in removing template is evaluated by analyzing MIP films before and after the treatment by X-Ray Photoelectron Spectroscopy (XPS) also evidencing the correlation between MIP chemical structure and its rebinding ability. Under the selected optimal conditions, MIP based sensor shows satisfactory performance in terms of sensitivity, limit of detection, reproducibility and selectivity.