Electrochemical sensor for bisphenol A determination based on MWCNT/melamine complex modified GCE

Based on the unique electronic properties and high adsorption capacity of carbon nanotubes as well as the electrostatic attraction between protonated melamine and negatively charged bisphenol A (BPA), a novel electrochemical sensor for the determination of BPA in water was fabricated by immobilization of multi-walled carbon nanotubes (MWCNTs)/melamine complex onto the surface of glassy carbon electrode. The cyclic voltammetry results showed that the sensor exhibited strong catalytic activity toward the oxidation of BPA with a well-defined cyclic voltammetric peak at 0.56 V. Moreover, the electrochemical sensor exhibited a wider linearity range from 10.0 nM to 40.8 μM BPA with a detection limit of 5.0 nM (S/N = 3). The enhanced performance of the sensor can be attributed to the combination of the excellent electrocatalytic property of MWCNTs and the electrostatic attraction of the protonated melamine to the negatively charged BPA. This novel sensor was successfully applied to determine BPA leached from real plastic samples with good recovery, ranging from 96% to 102%.