Development of copper electrochemical sensor using D-penicillamine functionalized graphene oxide modified electrode

In this research, graphene oxide (GO) was functionalized with D-penicillamine (DPA) and used to develop an electrochemical sensor for Cu(II) cation. For the successful synthesis of D-penicillamine-functionalized graphene oxide (DPA-GO), Fourier Transfer Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), X-ray diffraction pattern (XRD), and Transmission Electron Microscopy (TEM) are used. DPA-GO modified glassy carbon electrode (DPA-GO / GCE) was prepared and its electrochemical behavior was studied in the presence of Cu(II) cations by cyclic voltammetry, and the results showed the better performance of the DPA-GO-modified electrode compared to unmodified and GO-modified electrode, which related to GO nanostructure and complexing ability of sulfur, nitrogen, and oxygen-containing functional groups in the DPA structure. The prepared sensor was used for the selective and sensitive measurement of Cu(II) cations by square-wave anodic stripping voltammetry (SW-ASV) and the factors affecting the sensor performance were investigated and optimum conditions for sensor operation were determined. Under the optimal conditions, the prepared electrode has a linear response in the range of 1 pM to 0.1 µM and its detection limit was 0.31 pM. The proposed sensor was used satisfactorily to measure copper cation in real water samples with suitable reproducibility and stability.