Electrochemical Determination of Bisphenol A on a Glassy Carbon Electrode Modified with Gold Nanoparticles Loaded on Reduced Graphene Oxide-Multi-Walled Carbon Nanotubes Composite

A glassy carbon electrode (GCE) modified with gold nanoparticles loading on the reduced graphene oxide (rGO)-multi-walled carbon nanotubes (MWCNTs) composite film was fabricated by a two-step procedure. Firstly, rGO-MWCNTs composite were prepared by in-situ chemical reduction method with hydrazine as a reducing agent. Then, AuNPs were deposited on the surface of rGO-MWCNTs using simple cyclic voltammetry. This modified electrode was characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and electrochemical methods. Furthermore, the electrochemical behavior of bisphenol A (BPA) was also investigated using this modified electrode. The results showed that the modified electrode had high electrochemical activity for the oxidation of BPA. In 0. 10 mol/L phosphate buffer solution (PBS, pH 7. 0), the linear range for the determination of BPA with differential pulse voltammetry (DPV) was in the range of 5. 0 x 10(-9)-1. 0 x 10(-7) mol/L and 1. 0 x 10(-7)-2. 0 x 10(-5) mol/L. The detection limit was 1. 0 x 10(-9) mol/L (S/N = 3). The as. prepared modified electrode was successfully used to determine BPA in river water and the shopping receipt samples with recovery ranges of 97% - 110% and 98% - 104%, respectively.