Simultaneous determination of Cd and Pb was achieved by using graphene oxide/κ-carrageenan/l-cysteine (GO/κ-Car/l-Cys) nanocomposite modified glassy carbon electrode (GCE) by Square Wave Anodic Stripping Voltammetry (SWASV). The morphology and functionalization of the prepared nanocomposite were characterized by XRD analysis, Raman spectroscopy, Field emission scanning electron microscopy and FTIR analysis. Under optimum conditions, outstanding linearity was obtained for both Cd and Pb in the range from 5 to 50nM with the detection limits as 0.58nM and 1.08nM respectively. The sensitivity calculated from the slope of calibration curve was 1.39μA/nM and 1.32μA/nM for Cd and Pb respectively. We also carried out multiple metal ion detection, interference of anions and surfactants for the detection of Cd and Pb ions. The modified electrode has been applied to the detection of Cd and Pb present in water and milk samples, and the accessed results were satisfactory with that of AAS.
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http://dx.doi.org/10.1016/j.carbpol.2017.11.017 | DOI Listing |
Anal Methods
January 2025
College of Electrical and Electronic Engineering, Wenzhou University, Wenzhou 325035, China.
A flexible electrochemical sensor with high sensitivity and specificity is developed using gold nanoparticles (AuNPs) and a reduced graphene oxide/molybdenum disulfide (rGo-MoS) composite modified screen printed carbon electrode (SPCE), with L-cysteine (L-Cys) as a probe for Cu target recognition. Owing to the AuNPs/rGo-MoS, the electron transference ability is improved by increasing the specific surface area of the working electrode, and a high sensitivity is achieved. Meanwhile, the bidentate chelation of L-Cys to Cu contributes to a good selectivity.
View Article and Find Full Text PDFAnal Methods
November 2024
Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, 05508-000, Brazil.
This study introduces a cost-effective approach for quantifying uric acid (UA), the main antioxidant species in human physiology and implicated in inflammatory regulation. Using a PVC substrate and pencil drawing technique, electrodes were fabricated and modified with niobium oxide and graphene oxide a straightforward "drop casting" method. The nanostructures of the substrate, electrode, and modified electrode were evaluated using SEM images.
View Article and Find Full Text PDFMikrochim Acta
September 2024
Laboratory of Electrochemistry and PATLAB, National Institute of Research and Development for Electrochemistry and Condensed Matter, 202 Splaiul Independentei Street, 060021, Bucharest, Romania.
The significance of HER-1 and CA 125 lies in their ability to guide cancer diagnosis, treatment, and monitoring, improving personalized care and enhancing prognostic accuracy. The utilization of HER-1 and CA 125 as screening biomarkers for the anticipation of early-stage cancer and monitoring cancer progression is expanding due to the invasive and costly nature of present techniques. In this study, a novel stochastic sensor was developed for the simultaneous determination of HER-1 and CA 125 in whole blood, saliva, and gastric tumor tissue samples using a fast, easy, inexpensive, and portable method.
View Article and Find Full Text PDFLangmuir
June 2024
Faculty of Materials Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou, Jiangxi 341000, China.
l-cysteine, as an eco-friendly and nontoxic corrosion inhibitor, was directly covalently linked to the carbon/carbon double bonds of the GO flakes by a thiol-ene click reaction to avoid decreasing the number of hydrophilic oxygen-containing polar functionalities. The corrosion inhibition performances of Cys-GO toward Q235 steel (QS) in diluted hydrochloric acid were studied by electrochemical methods. The corrosion was a charge transfer-controlled process, and Cys-GO manifested as a mixed-type corrosion inhibitor.
View Article and Find Full Text PDFSensors (Basel)
March 2024
School of Materials Engineering, Wuhu Institute of Technology, Wuhu 241003, China.
A new, simple, and effective one-step reduction method was applied to prepare a nanocomposite with spherical polycrystalline silver nanoparticles attached to the surface of reduced graphene oxide (Ag@rGO) at room temperature. Equipment such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR) was used to characterize the morphology and composition of the Ag@rGO nanocomposite. A novel electrochemical sensor for detecting L-cysteine was proposed based on fixing Ag@rGO onto a glassy carbon electrode.
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