Publication: Fabrication of gold nanoparticles-mno2 modified electrode for heavy metal sensor
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Date
2024-08-01
Authors
Tan Min Yuan
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Abstract
The increasing global problem of heavy metal pollution demands rapid, responsive, and accurate techniques to identify these pollutants in environmental. Electrochemical sensors offer a promising solution due to their high sensitivity, low cost and portability. However, traditional electrochemical sensors often face limitations such as poor conductivity, instability, and limited selectivity. In this study, the Nafion/AuNPs-MnO2/ITO electrode was fabricated via drop-casting method. The influence of MnO2, specifically the type (commercial purchased from Sigma Aldrich and as-synthesized MnO2 using hydrothermal method) and concentration of MnO2 (2mg/mL,4mg/mL, 6mg/mL, 8mg/mL and 10mg/mL) as well as the amount of AuNPs (5μL, 10μL, 15μL, 20μL and 25μL), on the electrochemical performance of the modified electrode is investigated. The structural properties of commercial MnO2, as-synthesized MnO2 and AuNPs were characterized using X-ray diffraction (XRD) analysis. The electrochemical performance of the modified electrode was evaluated using cyclic voltammetry (CV) and square wave anodic stripping voltammetry (SWASV) analyses. The results revealed that the 1.0% Nafion/8mg MnO2-10μL AuNPs/ITO modified electrode exhibited significant improvement in the redox peak current and simultaneous detection of Cd(II), Pb(II), dan Cu(II) ions with limit of detection (LOD) of 275.667 ppb, 76.314 ppb, and 132.503 ppb and sensitivities of 0.055 μA/ppb, 0.064 μA/ppb, and 0.075 μA/ppb, respectively. The synergistic effects of MnO2 NPs and AuNPs and increased electroactive surface contribute to the enhanced electrochemical performance of the modified electrode.