Carbonaceous Materials-12: a Novel Highly Sensitive Graphene Oxide-Based Carbon Electrode: Preparation, Characterization, and Heavy Metal Analysis in Food Samples

Abstract

Graphene oxide (GO) was covalently attached to glassy carbon (GC) electrode (GC-O-GO) for fabricating nanosensors to determine trace Pb 2+ and Cd 2+ using differential pulse anodic stripping voltammetry (DPASV). Surface characterization of the nanofilm-covered electrode was performed via electrochemical cyclic voltammetry (CV), transmission electron microscopy (TEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) techniques. Surface pKa of the GO covalent attached GC (GC-O-GO) was calculated via CV. Under optimal conditions, a linear response was found for Pb 2+ and Cd 2+ in the range from 1×10 −8 to 1×10 −12 M. The limit of detections (LODs) of Pb 2+ and Cd 2+ were 0.25 pM and 0.28 pM, respectively. The method shows good reproducibility, and stability was successfully applied to measure Pb 2+ and Cd 2+ levels in rice, soya, milk, and tap water samples, with good agreement with those obtained by the standard inductively coupled plasma optical emission spectrometry (ICP-OES) method. The method was evaluated by application with the simultaneous determination of the ions in food samples (n=6) using the standard addition method. The recoveries of the Pb 2+ and Cd 2+ were up to 98 %.

Voltammetric determination of metal ions beyond mercury electrodes. A review

“…The use of the stripping mode, together with the incorporation of Nafion in the device design improves the detection limits of the method [102]. Carbon electrodes modified with graphene have also been considered [103,104]. In the first case, a graphene ultrathin film electrode is used for the analysis of Pb(II) with a good performance [103].…”

“…In the first case, a graphene ultrathin film electrode is used for the analysis of Pb(II) with a good performance [103]. A relevant increase in the sensitivity is allowed modifying covalently the surface of a GCE with graphene oxide for the analysis of Pb(II) and Cd(II) [104].…”

Gold Nanoparticles/Graphene Oxide Based Disposable Sensor System for Voltammetric Detection of Ceftizoxime

“…3-/4redox pair from the surface with electrostatic effects. Hence, the presence of GO on PGE impeded the electron transfer and reduced the peak currents [27]. When AuNP electrodeposition was performed onto GO film, AuNP/GO/PGE showed a welldefined CV, with approximately equal and reversible peaks (Fig.…”

Nanomaterials-Based Ion-Imprinted Electrochemical Sensors for Heavy Metal Ions Detection: A Review

“…In the electrochemical analysis of HMIs, GO prepared by the GR precursor system is more common because many oxygen functional groups (such as carboxyl and hydroxyl groups) are introduced into its GR monolayer, which can improve the dispersibility in solutions and provide enough binding sites for adsorbing HMIs [ 29 ]. Therefore, many ECSs for HMIs based on GO and its composites have been developed continuously [ 104 ].…”