▎ 摘　　要

Reduced graphene oxide (rGO) dispersion was obtained by ultrasonication of rGO powder using dodecanethiol (-SH) as an exfoliating agent. Using thiol chemistry, the gold nanoparticles (Au-NPs) were assembled onto the rGO-SH modified glassy carbon electrode (GCE) which showed a strong binding with the surface of the coated electrode. Furthermore, the GCE/rGO-SH/Au-NPs electrode was used to detect mercury (Hg2+) ions in the aqueous solution. When employed as a working electrode, Hg2+ ions get adsorbed on the electrode surface which was later electrochemically oxidized by differential pulse voltammetry (DPV) with the enhanced oxidation current at +0.172 V. Moreover, this sensor platform showed linear response for Hg detection from 1-10 mu M in phosphate buffer saline (PBS) solution and the detection limit was found to be 0.2 mu M (S/N = 3). The characterization of the Au-NPs and rGO-SH films were studied by Fourier-transform infrared spectroscopy (FT-IR), UV-Visible spectroscopy, transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE-SEM). The application of the prepared sensor was also demonstrated in detecting mercury ions in tap water samples with satisfactory recovery analysis. (C) The Author(s) 2018. Published by ECS.