Miniaturized electrochemical sensor with micropillar array working electrode for trace lead online measurement in tap water

TLDR: In this paper, a compact, durable, low-reagent-usage, portable miniaturized electrochemical sensor is successfully developed for the high sensitivity detection of trace lead in tap and lake samples.

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 of low baseline current and high peak current difference height. The analytical performance of the fabricated electrochemical sensor with three-dimensional gold (Au) working electrodes modified by Bismuth-film was comprehensively studied. The microsensor exhibited a high sensitivity of 0.0412μAppb−1 and a satisfactory detection limit of 0.15ppb when detecting lead ions under optimized conditions. Moreover, good linearity (correlation coefficient: 0.9993) with lead ions measurement in the concentration range of 1 to 120ppb 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.