PORTABLE NAFION-COATED GRAPHITE-BISMUTH NANOPLATE SENSOR INTEGRATED WITH VIBRATION-ASSISTED DETECTION FOR HEAVY METAL IONS

초록

Heavy metal contamination in natural water sources poses a critical threat to ecosystems and human health, even at trace levels. To address this challenge, we developed a portable electrochemical sensing system (vPES) equipped with a vibration unit for point-of-use (POU) detection of Pb2+ and Cd2+. The integrated vibration unit significantly enhances analyte diffusion, improving detection sensitivity. A Nafion-coated, graphite/bismuth-nanoplate-modified screen-printed carbon electrode was employed for selective and efficient heavy metal detection. Experimental and simulation results showed that the vibration-enhanced sensor achieved up to 540% and 511% increased signal responses for Pb2+ and Cd2+, respectively, compared to static conditions. The system achieved limits of detection of 0.98 nM (Pb-2.) and 1.65 nM (Cd2+) in laboratory tests. Its field applicability was demonstrated using real samples from the Nakdong River, as well as freshwater, soil, and serum specimens. These results validate the potential of vPES as a compact, rapid, and highly sensitive POU tool for environmental monitoring and public health protection.

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