51 research outputs found
Novel electrochemical synthesis of copper oxide nanoparticles decorated graphene-β-cyclodextrin composite for trace-level detection of antibiotic drug metronidazole
Over the past decades, the synthesis of inorganic and organic nanocomposites has received much attention in the range of fields including electroanalysis of organic chemicals. In this regard, we have prepared copper oxide nanoparticle (CuO NPs) decorated graphene/β-cyclodextrin (GR-β-CD) composites using a simple electrochemical methodology, where the CuO NPs are electrodeposited on GR-β-CD composite modified electrodes. A stable GR-β-CD composite was prepared by sonication of GR in β-CD aqueous solution. As-prepared GR-β-CD/CuO NPs composites were characterized by the high-resolution scanning electron microscopy, X-ray diffraction, and Raman spectroscopy. Cyclic voltammetry results reveal that the GR-β-CD/CuO NPs composite modified electrode exhibits an excellent catalytic activity and lower reduction potential towards the electrochemical detection of metronidazole (MTZ) over other modified electrodes including GR, GR-β-CD, and CuO NPs. Under optimized conditions, amperometry was used for the determination of MTZ using GR-β-CD/CuO NPs composite modified electrodes. The response of MTZ using the composite electrodes was linear over the range from 0.002 to 210.0 ¾M. This sensor showed the lowest limit of detection of 0.6 nM and was much lower than the previously reported MTZ sensors. In addition, the sensor is highly sensitive, selective and durable in the presence of a range of potentially interfering electroactive compounds
Synthesis and characterization of polypyrrole decorated graphene/β-cyclodextrin composite for low level electrochemical detection of mercury (II) in water
Mercury (Hg(II)) is considered as one of the most toxic element that directly affects the human health and the environment. Therefore, in this study, we propose a sensitive and disposable electrochemical sensor for the detection of Hg(II) in various water samples using polypyrrole (PPy) decorated graphene/-cyclodextrin (GR-CD) composite modified screen-printed carbon electrode (SPCE). The GRCD/PPy composite was synthesized by chemical oxidation of PPy monomer in GR-CD solution using FeCl3. Differential pulse voltammetry (DPV) is used for the detection of Hg(II) and the DPV results reveal that GR-CD/PPy composite modified SPCE has high sensitivity towards Hg(II) than bare, GR, GR-CD and PPy modified SPCEs. The optimization studies such as effect of pH, accumulating time and effect of scanning potential towards the detection of Hg(II) were investigated. The GR-CD/PPy composite modified SPCE could detect the Hg(II) up to 51.56 M Lâ1 with the limit of detection (LOD) of 0.47 nM Lâ1. The obtained LOD was well below the guideline level of Hg(II) set by the Worldâs Health Organization (WHO) and U.S. Environmental Protection Agency (EPA). In addition, the fabricated GR-CD/PPy composite modified SPCE selectively detected the Hg(II) in the presence of potentially interfering metal cations
Synthesis of two-dimensional nanosheet like samarium molybdate with abundant active sites: real-time carbendazimin analysis in environmental samples
Revealing the effect of multidimensional ZnO@CNTs/RGO composite for enhanced electrochemical detection of flufenamic acid
Synergistic design of a tin phosphate-entrapped graphene flake nanocomposite as an efficient catalyst for electrochemical determination of the antituberculosis drug isoniazid in biological samples
Two-dimensional titanium carbide (MXene) nanosheets as an efficient electrocatalyst for 4-nitroquinoline N-oxide detection
Recent Advances in Two-Dimensional MXene-Based Electrochemical Biosensors for Sweat Analysis
Sweat, a biofluid secreted naturally from the eccrine glands of the human body, is rich in several electrolytes, metabolites, biomolecules, and even xenobiotics that enter the body through other means. Recent studies indicate a high correlation between the analytesâ concentrations in the sweat and the blood, opening up sweat as a medium for disease diagnosis and other general health monitoring applications. However, low concentration of analytes in sweat is a significant limitation, requiring high-performing sensors for this application. Electrochemical sensors, due to their high sensitivity, low cost, and miniaturization, play a crucial role in realizing the potential of sweat as a key sensing medium. MXenes, recently developed anisotropic two-dimensional atomic-layered nanomaterials composed of early transition metal carbides or nitrides, are currently being explored as a material of choice for electrochemical sensors. Their large surface area, tunable electrical properties, excellent mechanical strength, good dispersibility, and biocompatibility make them attractive for bio-electrochemical sensing platforms. This review presents the recent progress made in MXene-based bio-electrochemical sensors such as wearable, implantable, and microfluidic sensors and their applications in disease diagnosis and developing point-of-care sensing platforms. Finally, the paper discusses the challenges and limitations of MXenes as a material of choice in bio-electrochemical sensors and future perspectives on this exciting material for sweat-sensing applications
Efficient photocatalytic degradation of textile dye pollutants using thermally exfoliated graphitic carbon nitride (TEâgâC3N4)
Abstract Graphitic carbon nitride (gâC3N4), an organic photocatalyst was reported to have beneficial properties to be used in wastewater treatment applications. However, gâC3N4, in its bulk form was found to have poor photocatalytic degradation efficiency due to its inherent limitations such as poor specific surface area and fast electronâhole pair recombination rate. In this study, we have tuned the physiochemical properties of bulk gâC3N4 by direct thermal exfoliation (TEâgâC3N4) and examined their photocatalytic degradation efficiency against abundant textile dyes such as methylene blue (MB), methyl orange (MO), and rhodamine B (RhB). The degradation efficiencies for MB, MO, and RhB dyes are 92âÂąâ0.18%, 93âÂąâ0.31%, and 95âÂąâ0.4% respectively in 60 min of UV light irradiation. The degradation efficiency increased with an increase in the exfoliation temperature. The prepared catalysts were characterized using FTIR, XRD, FE-SEM, EDAX, BET, and UV-DRS. In BET analysis, TEâgâC3N4 samples showed improved surface area (48.20 m2/g) when compared to the bulk gâC3N4 (5.03 m2/g). Further, the TEâgâC3N4 had 2.98 times higher adsorption efficiency than the bulk ones. The free radicals scavenging studies revealed that the superoxide radicals played an important role in the photodegradation for dyes, when compared to the hydroxyl radical (.OH) and the photo-induced holes (h+), Photoluminescence (PL) emission and electrochemical impedance spectroscopy (EIS) spectra of TEâgâC3N4 indicated a lowered electronâhole pairsâ recombination rate and an increased photo-induced charge transfer respectively. Further, the TEâgâC3N4 were found to have excellent stability for up to 5 cycles with only a minor decrease in the activity from 92% to 86.2%. These findings proved that TEâgâC3N4 was an excellent photocatalyst for the removal and degradation of textile dyes from wastewater
Robust and selective electrochemical detection of antibiotic residues: The case of integrated lutetium vanadate/graphene sheets architectures
Solvothermal synthesis of carbon incorporated MnS2 Spheres; high sensing performance towards the detection of furazolidone in bio-fluids
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