Ultra-sensitive, selective, and rapid carcinogenic 1,2-diaminobenzene chemical determination using sol–gel coating low-dimensional facile CuS modified-CNT nanocomposites by electrochemical approach

Ultrasensitive electrochemical sensor for vanillin based on CuS doped highly conductive carbon materials

Herein, a sensitive and selective electrochemical sensor modified with CuS doped highly conductive carbon materials (HCC) were successfully used to detect vanillin (VAN), which manufactured in a low temperature one step process. Experimental analysis by differential pulse voltammetry (DPV) and cyclic voltammetry (CV) under optimised conditions revealed excellent rate characteristics due to sub-micron spherical particles on the surface of CuS nanoparticles and synergistic effects with the excellent electrical conductivity of HCC. The prepared functionalized CuS-HCC/GCE has an ultra high specific surface area (10.85 mm2) and selective VAN determination, whose detection limit and linear range of VAN sensor are 61 pM and 0.1 nM-120 μM respectively, and has a terrific recovery rate in food samples (96.7 % to 103.8 %). These results show that this work has provided a new promising food sensor for detecting VAN.

CeO2·ZnO@biomass-derived carbon nanocomposite-based electrochemical sensor for efficient detection of ascorbic acid

Ascorbic acid (AA), a prominent antioxidant commonly found in human blood serum, serves as a biomarker for assessing oxidative stress levels. Therefore, precise detection of AA is crucial for swiftly diagnosing conditions arising from abnormal AA levels. Consequently, the primary aim of this research is to develop a sensitive and selective electrochemical sensor for accurate AA determination. To accomplish this aim, we used a novel nanocomposite comprised of CeO2-doped ZnO adorned on biomass-derived carbon (CeO2·ZnO@BC) as the active nanomaterial, effectively fabricating a glassy carbon electrode (GCE). Various analytical techniques were employed to scrutinize the structure and morphology features of the CeO2·ZnO@BC nanocomposite, ensuring its suitability as the sensing nanomaterial. This innovative sensor is capable of quantifying a wide range of AA concentrations, spanning from 0.5 to 1925 μM in a neutral phosphate buffer solution. It exhibits a remarkable sensitivity of 0.2267 μA μM-1cm-2 and a practical detection limit of 0.022 μM. Thanks to its exceptional sensitivity and selectivity, this sensor enables highly accurate determination of AA concentrations in real samples. Moreover, its superior reproducibility, repeatability, and stability underscore its reliability and robustness for AA quantification.

Low Overpotential Amperometric Sensor Using Yb2O3.CuO@rGO Nanocomposite for Sensitive Detection of Ascorbic Acid in Real Samples

The ultimate objective of this research work is to design a sensitive and selective electrochemical sensor for the efficient detection of ascorbic acid (AA), a vital antioxidant found in blood serum that may serve as a biomarker for oxidative stress. To achieve this, we utilized a novel Yb₂O₃.CuO@rGO nanocomposite (NC) as the active material to modify the glassy carbon working electrode (GCE). The structural properties and morphological characteristics of the Yb₂O₃.CuO@rGO NC were investigated using various techniques to ensure their suitability for the sensor. The resulting sensor electrode was able to detect a broad range of AA concentrations (0.5-1571 µM) in neutral phosphate buffer solution, with a high sensitivity of 0.4341 µAµM^-1cm^-2 and a reasonable detection limit of 0.062 µM. The sensor's great sensitivity and selectivity allowed it to accurately determine the levels of AA in human blood serum and commercial vitamin C tablets. It demonstrated high levels of reproducibility, repeatability, and stability, making it a reliable and robust sensor for the measurement of AA at low overpotential. Overall, the Yb₂O₃.CuO@rGO/GCE sensor showed great potential in detecting AA from real samples.

A Sensitive Hydroquinone Amperometric Sensor Based on a Novel Palladium Nanoparticle/Porous Silicon/Polypyrrole-Carbon Black Nanocomposite

Exposure to hydroquinone (HQ) can cause various health hazards and negative impacts on the environment. Therefore, we developed an efficient electrochemical sensor to detect and quantify HQ based on palladium nanoparticles deposited in a porous silicon-polypyrrole-carbon black nanocomposite (Pd@PSi-PPy-C)-fabricated glassy carbon electrode. The structural and morphological characteristics of the newly fabricated Pd@PSi-PPy-C nanocomposite were investigated utilizing FESEM, TEM, EDS, XPS, XRD, and FTIR spectroscopy. The exceptionally higher sensitivity of 3.0156 μAμM^-1 cm^-2 and a low limit of detection (LOD) of 0.074 μM were achieved for this innovative electrochemical HQ sensor. Applying this novel modified electrode, we could detect wide-ranging HQ (1-450 μM) in neutral pH media. This newly fabricated HQ sensor showed satisfactory outcomes during the real sample investigations. During the analytical investigation, the Pd@PSi-PPy-C/GCE sensor demonstrated excellent reproducibility, repeatability, and stability. Hence, this work can be an effective method in developing a sensitive electrochemical sensor to detect harmful phenol derivatives for the green environment.

Detection of L-Aspartic Acid with Ag-Doped ZnO Nanosheets Using Differential Pulse Voltammetry

Here, a sensitive voltametric electrochemical sensor probe was fabricated to reliably trace the detection of L-aspartic acid in phosphate-buffered medium using a glassy carbon electrode (GCE) layered with a film of wet-chemically prepared Ag2O-doped ZnO nanosheets (NSs). EDS, FESEM, XPS, and X-ray diffraction analyses were implemented as characterizing tools of prepared NSs to confirm the structural and compositional morphology, binding energies of existing atoms, and the crystallinity of synthesized NSs. The differential pulse voltammetry (DPV) was applied to the trace detection of L-aspartic acid, and exhibited a wide detection range of 15.0~105.0 µM, a limit of detection (3.5 ± 0.15 µM), and good sensitivity (0.2689 µA µM-1 cm-2). Besides these the precious reproducibility, stability, and efficient responses were perceived from the voltametric analysis of aspartic acid. Moreover, the proposed aspartic acid was subjected to experiments to potentially detect aspartic acid in real biological samples. Therefore, the development of an enzyme-free sensor by applying this method will be a smart technical approach in the near future.