A Novel Electrochemical Sensor Based on A Glassy Carbon Electrode Modified with GO/MnO₂ for Simultaneous Determination of Trace Cu(II) and Pb(II) in Environmental Water

Abstract

In this study, manganese dioxide hybridized with graphene oxide (GO/MnO2) nanocomposite was prepared by a facile synthesis method, which was applied to modify the glassy carbon electrode (GCE) in an electrochemical sensor of Cu(II) and Pb(II) for the first time. The morphology and structure of the nanocomposite were investigated by scanning electron microscopy, transmission electron microscopy and X‐ray diffraction, which exhibited MnO2 had been uniformly attached to the lamellar structure of GO, resulting in more adsorptive sites. Electrochemical properties of GO/MnO2/GCE were characterized by cyclic voltammetry and electrochemical impedance spectroscopy and the result confirmed GO/MnO2/GCE had an excellent electrochemical performance. Furthermore, the important factors affecting on the sensor sensitivity, including pH value, deposition potential, deposition time and material proportion were systematically investigated using square wave anodic stripping voltammetry (SWASV). The interferences from other ions on the target ion have also been discussed in this study. Under the optimal conditions, the GO/MnO2/GCE exhibited the linear ranges of 0.05 ∼ 1 μM for Cu(II) and Pb(II) with the detection limits of 1.67 nM and 3.33 nM, respectively, which was much lower than some electrochemical methods in reported literatures. The work provides a novel, simple and fast method for the simultaneous determination of Cu(II) and Pb(II).

MIL-88B(Fe)-NH2: an amine-functionalized metal–organic framework for application in a sensitive electrochemical sensor for Cd2+, Pb2+, and Cu2+ ion detection

“…5 (curve b), with regards to GCE/MIL-88B(Fe)-NH 2 , there are three peaks at −0.79 V, −0.52 V, and −0.02 V, which are associated with the presence of Cd 2+ , Pb 2+ , and Cu 2+ ions, respectively. 49 The results indicate that the GCE modied with MIL-88B(Fe)-NH 2 can be used as an electrochemical sensor for the determination of Cd 2+ , Pb 2+ , and Cu 2+ ions in aqueous solutions. DPV measurements of the GCE/MIL-88B(Fe)-NH 2 electrodes were performed in 0.1 M ABS (pH = 6.0) solutions containing 10 mM Cd 2+ , 10 mM Pb 2+ , and 10 mM Cu 2+ with differential measuring conditions, including potential step, pulse width, and pulse amplitude, in order to investigate the optimization studies for DPV, and the obtained results are described in Fig.…”

Fabrication of Screen-Printed Electrodes Modified by Hydrothermal MnO2 Microflowers and Carbon for Electrochemical Sensors in Copper Ions Detection

“…Obviously, at the more negative electrodeposition potential like −1.1 V, the total cathodic current increased, but the electrodeposition current of copper reduced due to the discharge competition of water to form hydrogen gas, namely, the hydrogen evolution phenomenon. At that time, the working electrode surface of the modifed SPEs chip was partially covered by hydrogen bubbles preventing the approach of Cu (II) ions to the working electrode surface to deposit [28]. As a result, following the diminished amount of electrodeposited copper on the working electrode surface, the anodic stripping current signal of copper in the correspondingly subsequent step degraded as well.…”

“…Among them, manganese dioxide (MnO 2 ) has gained great attraction due to its merits such as cheap cost, simple synthesis, low toxicity, and environmental friendliness. Accordingly, the MnO 2 materials with various morphologies such as zero-dimensional (0D) nanoparticles, onedimensional (1D) nanotubes, nanorods, nanowires and two-dimemsional (2D) nanosheets [22], and 3D complex architectures, for example, nanofowers [23], sea-urchins [24,25], hollow microspheres [26], and nanobowls [22,27,28] have synthesized and proved excellent heavy metal detection abilities.…”

“…Besides, for the sensor applications, the MnO 2 material reveals a disadvantage of poor electrical conductivity. To overcome this drawback, coupling MnO 2 with another conducting agent to produce composites has been proposed, for instance, the coupling of MnO 2 with graphene oxide (GO) or reduced graphene oxide (RGO) [28,29]. Introduction of graphene or GO into the MnO 2 material not only enhances the electrical conductivity property but also increases surface area and improves chemical stability for the synthesized composite materials.…”

Machine Learning Assisted Metal Oxide‐Bismuth Oxy Halide Nanocomposite for Electrochemical Sensing of Heavy Metals in Aqueous Media

“…There are many papers which discusses on various heavy metal ions determination such as lead, cadmium, copper, mercury, and chromium using electrochemical principle of detection. [11][12][13][14][15][16] There are comparatively limited research papers of deadly nickel ion determination based on electrochemical principle. Some papers which discussed nickel sensing using electrochemical method are 1) Glassy carbon electrode altered with chelating reagent Dimethylglyoxime (GCE/DMG) was employed to find trace metal nickel 2) Selenium as well as Nickel was deter- mined using Chitosan modified manganese oxide (Cn/Mn 3 0 4 ) sensor.…”