An amperometric sensor for bisphenol A based on graphene nanosheets containing bimetallic Pt-Pd nanoparticles

In this research work, at first, bimetallic Pt-Pd particles/ ERGO nanohybrid was prepared on glassy carbon electrode (GCE) and then was used to determine bisphenol A (BPA). The morphology of modified electrode was studied by using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and energy dispersive spectroscopy (EDS). Cyclic voltammetry (CV) of modified electrode in the presence of BPA in phosphate buffer indicated an oxidation peak at 0.44 V which means the irreversible oxidation process of this compound. In addition, electrochemical impedance spectroscopy results showed that charge transfer of Pt-Pd/ERGO/GCE is lower than GCE and ERGO/GCE. Amperometric method was applied as a sensitive analytical method for the determination of BPA. A linear relationship between the oxidation peak current and BPA concentration was obtained in the range from 5 to 201.5 µM with a detection limit of 0.75 µM and sensitivity of 0.13 µA µM-1. Moreover, the proposed electrode exhibits good selectivity for electrooxidation of BPA.