Miniaturized electrochemical sensor with micropillar array working electrode for trace lead online measurement in tap water
Abstract
A compact, durable, low-reagent-usage, portable miniaturized electrochemical sensor is successfully developed for the high sensitivity detection of trace lead. We fabricated micropillars array working electrodes on the chip and established ultra-low concentration sodium acetate-acetate (NaAC-HAC) buffers (pH ≈ 4.5) system to enhance the detection sensitivity of the sensor. The ultra-low concentration buffer possesses unique features such as low baseline current and high peak current difference height. The analytical performance of the fabricated electrochemical sensor with 3D gold (Au) working electrodes modified by bismuth-film was comprehensively studied. The microsensor exhibited a high sensitivity of 0.0412 µA ppb-1 and a satisfactory detection limit of 0.15 ppb when detecting lead ions under optimized conditions. Moreover, good linearity (correlation coefficient: 0.9993) with lead ion measurements in the concentration range of 1-120 ppb and excellent repeatability (RSD: 1.79%) was obtained, the chip has satisfactory selectivity for common interference ion. Besides, a low consumption of 350 µl of reagents per test was acquired. Finally, the proposed microsensor was applied to detect trace metal ions in tap and lake samples with satisfactory results.
- Publication:
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Journal of Micromechanics and Microengineering
- Pub Date:
- October 2019
- DOI:
- 10.1088/1361-6439/ab284e
- Bibcode:
- 2019JMiMi..29j5005H
- Keywords:
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- miniaturized sensor;
- micropillar array electrode;
- trace lead;
- ultra-low concentration buffer