Gold nanoparticles electrodeposited on glassy carbon using cyclic voltammetry: Application to Hg(II) trace analysis

Abstract

a b s t r a c tThe electrochemical determination of Hg(II) at trace level using gold nanoparticles-modified glassy carbon (AuNPs-GC) electrodes is described. Starting from HAuCl 4 in NaNO 3 , gold nanoparticles (AuNPs) were deposited onto Glassy Carbon (GC) electrodes using Cyclic Voltammetry (CV). Different deposits were obtained by varying the global charge consumed during the whole electroreduction step, depending on the number of cyclic potential scans (N). AuNPs were characterized as a function of the charge using both CV in H 2 SO 4 and Field Emission Gun Scanning Electron Microscopy (FEG-SEM). The AuNPs-GC electrodes were then applied to determine low Hg(II) concentrations using Square Wave Anodic Stripping Voltammetry (SWASV). The AuNPs-GC electrodes provided significantly improved performances in Hg(II) determination compared to unmodified GC and bare Au electrodes. It was shown that the physico-chemical properties of the deposits are correlated to the performances of the AuNPs-GC electrode with respect to Hg(II) assay. The best results were obtained for four electrodeposition cyclic scans, where small-sized particles (36 ± 13 nm) with high density (73 particles lm À2 ) were obtained. Under these conditions, a linearity range from 0.64 to 4.00 nM and a limit of detection of 0.42 nM were obtained.

A Practical Approach in Glycerol Oxidation for the Development of A Glycerol Fuel Cell

“…However, it was not observed a clear evidence of glycerol oxidation during the experiment. Also, the GC-Au showed lower current densities than the gold electrode, the reasons for this are may be related to the size of the gold layer, the GC-Au stability and possibly intrinsic resistances between the materials [37]. Figure 10d shows the CV of gold and GC-Au electrodes in 1 M glycerol in 1 M NaOH.…”

Electrochemical Preparation and Characterization of a Gold Nanoparticles Graphite Electrode: Application to Myricetin Antioxidant Analysis

“…The electrodeposition procedure used was based on a proposed method by Hezard et al, 13 and potential steps of 0.0025 V. A total of 20 repetition cycles were performed for each activation. The surface-modified electrode was designated to be an AuNPs/graphite electrode.…”

“…This peak was associated with the reduction of gold(III) to elemental gold. 13,29 When the CV results were analyzed from the 1st to the subsequent 3rd and 10th CV, the peak shifted to a more positive potential, with the first scan and the 10th scan being recorded at 0.55 and 0.71 V, respectively. No significant peak potential shift was observed after the 10th scan.…”

“…1 Various deposition procedures of gold nanoparticles (AuNPs) on carbon electrodes have been studied including electro-polymerization, [5][6][7][8] electro-grafting methods 9,10 and electro-deposition. [11][12][13][14][15] The latter method provides a much easier, rapid and lower cost procedure 13 because the preparation is less tedious and involves minimum chemical usage.…”

One-pot organometallic synthesis of well-controlled gold nanoparticles by gas reduction of Au(I) precursor: a spectroscopic NMR study

“…The development of simple methods to obtain AuNPs which are able to form thin films on substrates is therefore of great interest. Recently, different electrochemical methods were investigated for the deposition of AuNPs on glassy carbon electrodes for Hg(II) trace detection in water [20,21]. Despite good performance with a detection limit of 0.40 nmol of Hg.L −1 , no control of shape and dispersisty of AuNPs smaller than 15 nm were obtained by electrodeposition of HAuCl 4 in sodium nitrate electrolyte.…”