Electrochimica Acta, Vol.305, 329-337, 2019
Directly-thiolated graphene based electrochemical sensor for Hg(II) ion
In this study, an electrochemical sensor toward mercury ion was developed. As the sensing material directly-thiolated graphene (G-SH) was used. After the graphene synthesis and its characterization (elemental analysis, FT-IR and Raman spectroscopy, scanning electron microscopy), the best measurement conditions were chosen and working parameters of the sensor were evaluated. The G-SH thin film was formed on the glassy carbon electrode surface by drop-casting. Mercury ion concentration was determined with the use of voltammetric techniques by comparison of current change of redox indicator hexaammineruthenium(III) chloride. As was found, the sensor response is strictly dependent on the G-SH amount deposited at the electrode surface and the pH of the sample. The prepared sensor demonstrated linear response within the range of 5 x 10(-9) to 5 x 10(-7) mol L-1 and high selectivity towards Hg(II) ion over other examined cations (e.g. Sr2+, Fe3+, Co2+, Pb2+, Mg2+ and for Ca2+). (C) 2019 Elsevier Ltd. All rights reserved.