A study of nanostructured gold modified glassy carbon electrode for the determination of trace Cr(VI)

Abstract

A nanostructured gold modified glassy carbon electrode (Au nano /GCE) was employed for the determination of trace chromium(VI). To prepare Au nano /GCE, the GCE was immersed into KAuCl 4 solution and electrodeposition was conducted at the potential of -0⋅4 V (vs Ag/AgCl) for 600 s. Scanning electron microscopy measurements show that the electrochemically synthesized gold nanoparticles were deposited in aggregated form. Any undue effects caused by the presence of foreign ions in the solution were also analysed to ensure that common interference in the determination of chromium(VI) by square wave voltammetry, do not influence the electrochemical response of the latter element. The results show that this method allows for Cr(VI) determinations with a much lower detection limit (0⋅01 µg L -1 ) in the presence of excess of Cr(III) than the commonly used diethylenetriammine pentaacetic acid (DTPA) method. The method was applied to determine levels of chromium(VI) in tap water and sewage water.

Determination of ppt Level Chromium(VI) Using the Gold Nano-Flakes Electrodeposited on Platinum Rotating Disk Electrode and Modified with 4-Thiopyridinium

“…The detection limit was of 1.09 ppt based on three times the standard deviation of the baseline [24]. Although the accumulation time was shorter, the PET/nano-Au/Pt-RDE still showed the LOD lower than the LOD of previous studies [2]-[6] [10]- [20].…”

“…Several recent works have been based on the layer of gold nanoparticles for improvement of electrochemical detection of Cr(VI) for instance gold nanoparticle-modified glassy carbon electrode by electrodeposition [24] or gold nanoparticle-modified titania nanotubes electrode by photo-deposition [25]. Moreover, Ouyang et al used 4-pyridine-ethanethiol (PET) to functionalize the gold nanoparticles on a glassy carbon electrode for accumulation of Cr(VI) in fluoride buffer (pH 4.5) before voltammetric determination by cathodic stripping square wave voltammetry [3].…”

Electrochemical Determination of Chromium(VI) in River Water with Gold Nanoparticles-Graphene Nanocomposites Modified Electrodes

“…Graphene/ AuNPs/GCE also offered excellent repeatability with a relative standard deviation (RSD) of about 1.70% for 5 repeated measurements of 5.00 μM Cr(VI). Compared with previously published methods with gold based electrodes, [10][11][12][13][14][15][16][17][18] the Graphene/ AuNPs/GCE offers the advantages of a satisfied detection limit, convenient detection procedures and simple electrode preparation, which fulfills the requirement for potential practical applications.…”

“…Gold nanoparticles (AuNPs) or nanostructured gold modified electrodes have been developed due to their favorable characteristics in the enhancement of electron-transfer processes with respect to the polycrystalline gold electrode. [10][11][12][13][14][15][16][17] The graphene-based nanomaterials is also being used for electrochemical sensing applications with greater frequency because of unique properties, such as high conductivity, excellent mechanical property and large active surface area. [18][19][20][21][22][23] A modified electrode with AuNPs and graphene nanocomposites for the detection of Cr(VI) was first reported by Santhosh and coworkers.…”

Characteristics of Voltammetric Determination and Speciation of Chromium – A Review

“…Recently, the disposable screen-printed electrodes modified with poly-l-histidine film [165], gold nanoparticles [166] and silver or gold nanoparticles [167] have been applied as a voltammetric sensors for the voltammetric determination of Cr(VI). Moreover, nano-sized gold particles deposited on glassy carbon [168] or on the conductive substrate modified with sol-gel derived thiol [169] were also used to the mention above purpose.…”