A Novel Sensing Platform Based on Metal Tungstate/g-C3N4 Nanocomposite for the Sensitive Electrochemical Detection of Ascorbic Acid

A novel NiWO4/CuWO4/g-C3N4 (NCWG) nanocomposite with excellent electrocatalytic activity was prepared and deposited on Indium-Tin Oxide (ITO) electrode for the electrochemical detection of ascorbic acid (AA). The two-dimensional dispersion of NiWO4 and CuWO4 on the g-C3N4 surface gave a more electroactive surface, subsequently influencing the current intensity of the electro-oxidation of AA. A significant increase of the oxidation current peak of AA at NCWG/ITO was observed and compared to the one obtained at other modified or unmodified ITO electrodes. The analytical parameters of the working electrode NiWO4/CuWO4/g-C3N4 vs. Ag/AgCl at an applied potential of - 0.05 V were reported utilizing the amperometric technique. A linear correlation between peak current and AA concentration in the range of 0.1 to 100 mu M was obtained with a detection and quantification limits of 0.1 mu M/L and 0.35 mu M/L, respectively, and a sensitivity of 1.22 mu A mu M-1 cm(-2). The novel sensor reveals sensitivity, reliability, and stability, allowing the sensitive determination of AA in tap water samples with satisfactory recoveries.