Selective Electrochemical Sensor for BPA Detection in Wastewater Using Molecularly Imprinted Polymers on Sustainable Magnetic Graphene Oxide

A modified screen-printed carbon electrode (SPCE) has been developed for the determination of bisphenol A (BPA), a compound widely used in plastics and resins production which can disrupt endocrine and reproductive human systems. Magnetic graphene oxide (MGO) was synthesized following a sustainable protocol based on mechanochemistry. Then, MGO was combined with a molecularly imprinted pyrrole-based polymer (MIPPy) for the preparation of a novel magnetic nanocomposite (BPA@MIPPy), being characterized by several imaging, spectroscopic and electrochemical techniques. The magnetic properties of BPA@MIPPy allowed the manipulation of the material, including separation, analyte preconcentration and electrode modification. Differential pulse voltammetry (DVP) was the selected electrochemical technique for BPA detection, presenting high sensitivity (LOD = 29 nM, LOQ = 97 nM) and precision under optimum conditions. To study selectivity, the response of the sensor towards four potential interferents was evaluated (phenol, methanol, sodium nitrate and ascorbic acid), and no interference was observed. Finally, a real wastewater sample was successfully analyzed, demonstrating to be adequate for water-control applications.