Voltammetric Determination of Trace Zn(II) in Seawater on a Poly(sodium 4-styrenesulfonate)/Wrinkled Reduced Graphene Oxide Composite Modified Electrode

Abstract

In this study, a novel poly(sodium 4-styrenesulfonate)/wrinkled reduced graphene oxide composite modified glassy carbon electrode (GCE) was prepared successfully. This electrode was used for sensitive detection of trace Zn(II) in seawater by differential pulse voltammetry (DPV). The morphology and electrochemical property of the modified electrode was characterized using scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), Fourier Transform Infrared (FT-IR) spectroscopy, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Results showed that the wrinkled graphene layer formed on the electrode surface could significantly promote the electron-transfer and increase the specific surface area of the electrode. Additionally, the poly(sodium 4-styrenesulfonate) film could also effectively improve the stability of the modified electrode, absorb cations and repel anions on the electrode surface. Under the optimal conditions, the linear response to Zn(II) obtained at the modified electrode, was in the range of 5 to 720 nM with a detection limit of 1.67 nM (S/N = 3). Practical applicability of this modified electrode was successfully tested for the determination of Zn(II) in seawater samples with satisfactory results.