Emerging applications of sustainable modified CdO/Ag-CdO NPs for electrochemical sensitive and selective detection of mercury (Hg) heavy metal.

The sensitivity of developed electrode has gained significant attention for potential energy storage and electrochemical sensor activities. The modified nano-CdO/Ag-CdO-carbon paste electrodes were developed for electrochemical detection of mercury (Hg) heavy metal. The synthesized samples were well characterized through PXRD (Powder X-ray diffraction), SEM-EDAX (Scanning Electron Microscopy-Energy Dispersive X-ray Analysis), XPS (X-ray photo-electron spectroscopy), FT-IR (Fourier transform Infra-Red), and UV-Visible spectroscopy. The Ag-CdO modified electrode endowed with higher sensing current and Csp (188 F/g) than pure CdO NPs (94.6 F/g) measured by Linear Sweep (LS), Cyclic Voltammetric (CV) and Electrochemical Impedance Spectral (EIS) techniques. The excellent electrochemical sensing action of developed Ag-CdO electrode was examined on heavy metal Hg ions at 1-5 mM scan rate in 0.1 M KCl. The linear relationship of sensing measurements with smaller concentration (1-5 mM) was observed with its increased current (+ 1.64 × 10 A/cm at 1 mM) at 30 mV/s. LOD of CdO and Ag-CdO electrodes (Hg ) were found at 1.91 mM & 2.41 mM (Hg ) respectively with maximum sensitivity at -0.006 V. LOQ of CdO and Ag-CdO electrodes (Hg ) were 5.78 mM & 6.98 mM respectively with maximum sensitivity at -0.006 V. The antibacterial measurements of prepared samples were examined for their susceptibility to inhibit the growth of gram-negative (Escherichia coli) and gram-positive (Staphylococcus aureus) bacteria. Thus, the synthesized Ag-CdO electrode provides a new insight for determining the concentrations of critical pollutants and processing the various nanoparticles for sensing of cyanogenic heavy metals.