Rapid Detection of Trace Pb(II) in Water Using a Rod-Shaped Bismuth-Based Electrode
This study presents a novel electrochemical sensor for the rapid detection of trace lead ions (Pb(II)) in water, utilizing a rod-shaped bismuth-based electrode. The electrode was fabricated by modifying a glassy carbon electrode (GCE) with basic bismuth nitrate [Bi6O5(OH)3](NO3)5·3H2O, synthesized via a chemical precipitation method. The sensor was characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), electron probe microanalysis (EPMA), and energy-dispersive X-ray spectroscopy (EDS), confirming the rod-like morphology and composition. Electrochemical detection was performed using differential pulse voltammetry (DPV) in a 0.1 mol·L−1 NaAc-HAc buffer (pH 4.3). The sensor exhibited a linear detection range for Pb(II) from 1 to 90 μg·L−1, with a detection limit of 0.34 μg·L−1 and a sensitivity of 106 μA·(μmol·L−1)−1. The electrode demonstrated excellent anti-interference capability and reproducibility. Recovery tests in real water samples (tap water and campus lake water) yielded high recovery rates, indicating practical applicability. This work provides a simple, cost-effective, and reliable method for monitoring trace Pb(II) in environmental water, particularly relevant for public swimming pools and similar aquatic facilities.