FABRICATION OF MERCURY SENSOR USING DITHIZONE-MODIFIED GRAPHENE QUANTUM DOTS
Keywords:
Graphene quantum dots, Dithizone, Mercury detection, Electrochemical sensor, Heavy metal monitoringAbstract
This study presents the fabrication and evaluation of a mercury sensor based on dithizone-modified graphene quantum dots; GQDs. The sensor was fabricated using a filter paper coated with GQDs and functionalized with dithizone, then assembled with gold electrodes for electrochemical measurement. The sensor was tested with various concentrations of mercury (II) chloride to evaluate its sensing performance. The results revealed a noticeable shift in color. The color changed from blue to orange, indicating the formation of a complex between mercury ions (Hg2+) and dithizone-modified GQDs. Electrical measurements revealed a non-ohmic current-voltage response with a consistent threshold voltage of approximately 2.50 V across all conditions. The sensor exhibited a clear correlation between mercury concentration and sensor response, where increased resistance and decreased conductivity corresponded to higher Hg2+ levels. Linear regression analysis showed a strong correlation, indicating high sensitivity and potential for quantitative detection. These results suggest that the proposed sensor was a promising low-cost, portable, and reliable tool for monitoring mercury contamination in environmental settings.
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