Selective electrochemical sensor for bisphenol A quantification on carbon electrodes modified with graphitic mesoporous carbon

Abstract

Owing to the unique electronic properties, high electrical conductivity, and high adsorption capacity of graphitic mesoporous carbon (GMC), a simple strategy was developed to alter the surface of glassy carbon electrodes with a thin layer of GMC. These modified electrodes were applied to detect bisphenol A (BPA) in wastewater samples due to the strong attraction between the GMC-modified surface and BPA. Electrochemical BPA sensing processes were evaluated using different electrochemical techniques, such as differential pulse voltammetry and cyclic voltammetry. For all electrochemical experiments, a distinguished anodic peak at ~ 0.55 V was observed, which was attributed to the enhanced electrochemical BPA oxidation on the surface of the GMC-modified electrode. In addition, the influence of scan rate and electrolyte pH on the electrochemical oxidation of BPA were studied in detail. The electrochemical sensor exhibited a reliable quantification of BPA in a wide range of BPA concentrations (i.e., 20 – 300 μM) and pH (i.e., 5.5 – 8.9) with a sensitivity of 2.93 μA μM−1 cm−2 and a detection limit of 59 nM. Finally, the pre-determined parameters were applied for the quantification of BPA in secondary-treated sewage. The results showed that the developed electrochemical sensor exhibited high BPA recovery in the range of 98.13 – 100.36 %. In summary, the developed electrochemical sensor showed satisfactory reproducibility and sensitivity for accurate BPA detection even in complex matrices, such as sewage.