Bisphenol-A electronalysis employing carbon coated superparamagnetic nanoparticles for adsorption and magnetic concentration onto screen-printed electrodes

Abstract

Bisphenol A (BPA) is a critical endocrine disrupter and estrogenic chemical found in plastics, food, water and specially, in thermal receipt paper, and its frequent monitoring is of great relevance because of the health and environmental concerns. Many electroanalytical methods have been reported for BPA, however the electrode poisoning effects observed for this analyte remains a drawback deserving additional efforts for improving the current methodologies. Here, a practical approach has been devised for routine use, encompassing screen-printed electrodes and a minipotentiostat, but incorporating an innovative design based on superparamagnetic nanoparticles combined with active carbon, an effective absorbing substrate for BPA. By attracting the superparamagnetic nanoparticles with an external, miniature Nd2Fe14B magnet, it was possible to concentrate the analyte onto the working electrode, thus enhancing and improving the electrochemical signal, while protecting the working electrode against the poisoning effect. The method was successfully applied to the analysis of BPA in real samples, yielding excellent results for this type of electrode, with a detection limit of 2.1×10−7molL−1 and quantification limit of 6.9×10−7molL−1.