Effect of different copper salts on the electrochemical determination of Cu(II) by the application of the graphene oxide-modified glassy carbon electrode

In this study, graphene oxide and reduced graphene oxide nanoparticles were synthesized by Hummers method and characterized Fourier transform infrared spectroscopy, X-ray diffraction spectroscopy, scanning electron microscopy and thermogravimetric analysis. Then, glassy carbon electrode surfaces were modified with synthesized and characterized graphene oxide (GO) and reduced graphene oxide (red-GO) using physical immobilization. Bare and modified surfaces were characterized by cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. Application of graphene oxide (GO/GC) and reduced graphene oxide-modified glassy carbon (red-GO/GC) surfaces for the electrochemical determination of copper(II) using different copper salts such as CuSO4·5H2O, Cu(NO3)2·3H2O and CuCI2 were performed by differential pulse voltammetry. The GO/GC surface was found to be suitable for selective determination of Cu(II) in the solutions containing the mixture of heavy metal ions (Zn(II), Pb(II), Cd(II), Fe(III) and Mn(II)) and showed high stability and reproducibility. The GO/GC surface was treated with CuSO4·5H2O, Cu(NO3)2·3H2O and CuCI2 salts solution in optimum conditions and afterward SEM images were measured 10 µm in size and radius of these ions in Cu(II)/GO/GC surfaces. Thus the determination of copper ions on the GO/GC surface was made for the first time by comparing the effect of the types of copper salts. When it was evaluated in terms of inorganic theory, the results were found to be in harmony.