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.

Multilayer Epitaxial Graphene on Silicon Carbide: A Stable Working Electrode for Seawater Samples Spiked with Environmental Contaminants

“…Multilayer epitaxial graphene was synthesized from a conducting N + , Si-face, 4° off-axis towards the [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ], 4H − silicon carbide (SiC) substrate via Si sublimation. The synthesis took place in a commercial chemical vapor deposition reactor at a temperature of 1550 °C and a pressure of 100 mbar in an Ar ambient atmosphere [ 18 ].…”

“…There has been recent interest in the use of graphene for electrochemical detection. Graphene is a promising material for the fabrication of highly sensitive working electrodes; it has unique physical and electrical properties that have been reviewed for a variety of electroanalytical applications [ 13 , 14 , 15 , 16 ].…”

Recent developments in ionophore-based potentiometric electrochemical sensors for oceanic carbonate detection

“…65 The type of voltammetry used (e.g., cyclic voltammetry, differential pulse voltammetry, square wave voltammetry, and chronoamperometry) depends on how the potential is varied. Current voltametric sensors for ocean-based research can measure pH and various trace metals (e.g., Zn 2+ , Cd 2+ , and Pb 2+ ) and ions (e.g., NO 3 − , NO 2 − , HPO 4 2− , PO 4 3− , and 37,[66][67][68][69][70][71][72][73][74][75][76] While these sensors have great analyte versatility, no voltametric sensors currently detect carbonate and sensor lifetime is limited. 37,65 The lifetime of these sensors depends on the number of measurements recorded by the electrode, and frequent measurements age the electrode until peak potential cannot be reached.…”

Modifications of Epitaxial Graphene on SiC for the Electrochemical Detection and Identification of Heavy Metal Salts in Seawater

“…Graphene has several unique physical and electrical properties, such as high electron mobility, high mechanical strength, and a high surface-to-volume ratio, which enable its use as a working electrode for various electroanalytical applications [ 12 , 13 , 14 , 15 ], including the detection of heavy metal ions in water [ 14 , 15 , 16 , 17 ]. While graphene can be synthesized by a variety methods [ 14 ], epitaxial graphene (EG) formed by sublimation of silicon (Si) from the Si-face of silicon carbide (SiC(0001)) is particularly attractive because it can be grown as a continuous layer with low defect density over wafer-scale areas, does not require transfer to another substrate, is not prone to aggregation issues [ 14 , 18 ], can be produced with a reproducible surface [ 11 ], and is compatible with semiconductor processing methods.…”