Glassy Carbon Electrodes Decorated with HgO/CNT Nanocomposite and Modified with a Conducting Polymer Matrix for Enzyme-Free Ascorbic Acid Detection

Abstract

In an alkaline solution, mercuric oxide decorated carbon nanotube nanocomposites (HgO.CNT NCs) were manufactured utilizing an uncomplicated wet-chemical approach. Ultra-Violet spectroscopy (UV-Visible), Fourier Transform Infra-red spectroscopy (FTIR), Powder X-ray Diffraction (XRD), X-ray Photo-electron Spectroscopy (XPS), and Field Emission Scanning Emission Microscopy (FESEM), X-ray Electron Dispersive Spectroscopy (XEDS) techniques were applied to examine the HgO.CNT NCs that had been prepared. Ascorbic acid sensor was developed upon light coating of HgO.CNT NCs on polished Glassy carbon electrode (GCE) modified with nafion (Nf). Analytical performance of the selected ascorbic acid sensor was achieved such as sensitivity, Limit of quantification (LOQ), Limit of detection (LOD), Linear dynamic range (LDR), extended reliability, interference effect experimentation, and actual sample inspection using a consistent current-voltage approach. Calibration curve of the suggested sensor was observed to be linear (R2=0.9957) throughout a broad range of ascorbic acid concentrations (100.0 pM∼100.0 mM) at a voltage of 0.8 V. The calibration curve yielded analytical parameters such as sensitivity (632.91 pAμM−1cm−2), LOQ (255.0 pM), LOD (76.50 pM), and LDR (100.0 pM ∼1.0 mM) for the proposed ascorbic acid sensor (GCE/HgO.CNT NCs/Nf). The wet-chemical synthesis of HgO.CNT NCs is a good development of nanocomposite-oriented sensor advancement in medical sciences with non-enzymatic detection of biological substances. This proposed sensor applied to selective ascorbic acid detection in biological samples and obtained logical outcomes.