Voltammetric Determination of Hydrochlorothiazide at SnO2-NiO Nanocomposite/Ionic Liquid Modified Carbon Paste Electrode

Herein, SnO2-NiO nanocomposite was prepared via a hydrothermal method and characterized by various techniques consisting X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectroscopy (EDS). The FESEM image showed particles with the size at about 20–130 nm in diameters. The electrochemical oxidation of hydrochlorothiazide (HCTZ) at a carbon paste electrode modified with SnO2-NiO nanocomposite and an ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF6)) (SnO2-NiO/IL/CPE) was evaluated in phosphate buffer (PB) pH 8, by using cyclic voltammetry, linear sweep voltammetry, differential pulse voltammetry and chronoamperometry. The SnO2-NiO/IL/CPE indicated a good electrocatalytic behavior towards to oxidation of hydrochlorothiazide. The anodic peak currents were increased with the HCTZ concentration and indicated two linear dynamic range from 0.01 to 0.1 µM and 0.1 to 100 µM and a detection limit of 0.002 µM (S/N = 5) under the optimized conditions. The introduced electrochemical sensor was utilized for the determination of HCTZ in the pharmaceutical formulations and biological sample.