Electrochemical detection of bisphenol A at graphene/melamine nanoparticle-modified glassy carbon electrode

Abstract

Due to the unique electronic properties and high adsorption capacity of graphene, a facile strategy was developed to form graphene/melamine nanocomposite by anchoring melamine molecule on the surface of graphene sheets. As the electrostatic attraction happened between protonated melamine and negatively charged bisphenol A (BPA), a novel electrochemical sensor was fabricated to determine the endocrine disruptor BPA by depositing graphene/melamine nanocomposite on the surface of glassy carbon electrode. The electrochemical behavior of BPA was investigated in phosphate buffer solution (pH 7.0) using the prepared sensor. A well-defined anodic peak at 0.56 V was found to attribute to the electrooxidation of BPA on the modified electrode. The kinetic parameters, charge transfer coefficient, electron transfer number, proton transfer number, and standard rate constant were calculated and optimized. The electrochemical sensor exhibited a wider linear range of 1.0 × 10−8 to 2.0 × 10−4 M BPA and a lower detection limit of 4.0 × 10−9 M (S/N = 3). This novel sensor was successfully applied to determine BPA leached from real plastic samples with good recoveries ranging from 97.00 to 100.96 %.