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Recently, semiconductor nanomaterials have gained interest amongst researchers because of their good electrocatalytic properties. Two dimensional (2D) transition metal dichalcogenide materials, NiSe2 have good physical, chemical, and transport properties for sensing applications. The present work demonstrates the fabrication of NiSe2‐graphene oxide (NiSe2−GO) modified glassy carbon electrode for the determination of carbamazepine (CBZ). The prepared nanocomposite was characterized by XRD, SEM and FT‐IR spectral methods. CBZ exhibited an irreversible oxidation peak at 0.85 V on NiSe2−GO/GCE in phosphate buffer of pH 7.0. A 54‐fold enhancement in oxidation peak current was observed at NiSe2−GO/GCE when compared to that at bare GCE. Sensing performance of NiSe2−GO/GCE was optimized by varying peak current dependent parameters. Linear relationship between the peak current and concentration of CBZ was observed in the range of 4.50×10−8–3.22×10−5 mol L−1 for differential pulse voltammetric method and 2.32×10−8–4.79×10−5 mol L−1 for square wave voltammetric method. The practical utility of the proposed sensor, was demonstrated by determining CBZ in pharmaceutical formulations and spiked urine samples. [ABSTRACT FROM AUTHOR]

Herein, we have reported on a simple, environmentally friendly, and ultra-sensitive electrode material, SnO2@p-rGO, used in a clean sustainable manner for rapid electrochemical determination of an anti-diabetic agent, repaglinide (RPG). Three-dimensional porous reduced graphene oxide nanostructure (p-rGO) was prepared via a low-temperature solution combustion method employing glycine. The aqueous extract of agricultural waste "cotton boll peel" served as stabilizing and reducing agents for the synthesis of SnO2 nanoparticles. The structural and morphological characterization was carried out by XRD, Raman, SEM, EDX, FTIR, absorption, and TGA. The oxidation process of RPG was realized under adsorption controlled with the involvement of two protons and electrons. The sensor displayed a wider linearity between the concentration of RPG and oxidation peak current in the ranges of 1.99 × 10−8–1.45 × 10−5 M and 4.99 × 10−8–1.83 × 10−5 M for square-wave voltammetric and differential pulse voltammetric methods, respectively. The lower limit of detection value of 0.85 × 10−9 M was realized with the SWV method. The proposed sensor was applied for the quantification of RPG in fortified urine samples and pharmaceutical formulations. Furthermore, the sensor demonstrated reproducibility, long-term stability, and selectivity in the presence of metformin and other interferents, which made the proposed sensor promising and superior for monitoring RPG. [ABSTRACT FROM AUTHOR]

1-D nanostructured metal oxides exhibit high selectivity having efficient catalytic trends toward a number of analytes. Tungsten oxide (WO3) is known for its catalytic properties, conductivity, and stability, which can be further enhanced by doping. This study deals with the synthesis of hafnium-doped tungsten oxide (Hf.WO3) nanorods via a hydrothermal process and their characterizations using X-ray diffraction, transmission electron microscopy, scanning and transmission electron microscopy, and X-ray photoelectron spectroscopy. The materials developed were used to fabricate an electrochemical sensor by modifying the carbon paste electrode (CPE), which was utilized to estimate paracetamol (PAR) and salbutamol (SBM) drugs. The results showed enhanced peak current compared to the nascent CPE, indicating facile transfer of the electrons. The catalytic properties, conductive nature, and broad surface area of the prepared 1-D nanostructures have shown remarkable improvement to detect the chosen analytes. A square wave voltammetric technique was also used to estimate detection limits of 1.28 × 10–9 and 2.42 × 10–9 M for PAR and SBM, respectively. The estimation of PAR and SBM in biological samples and pharmaceutical doses of the drugs demonstrated the usefulness of the sensor device for real analytical applications. [ABSTRACT FROM AUTHOR]