Simultaneous determination of trace Pb(II), Cd(II), and Zn(II) using an integrated three-electrode modified with bismuth film

摘要

Developing a reliable, sensitive and portable electrochemical sensor for precise determination of trace heavy metal ions in water is an attractive challenge. In this work, an integrated three-electrode sensor based on screen-printed gold working electrode (SPAuE) ex-situ electroplated bismuth film was developed via a facile and simple process for the determination of trace Pb(II), Cd(II), and Zn(II) by square wave anodic stripping voltammetry (SWASV). The bismuth film was deposited on SPAuE at a potential of -0.08 V (Bi/SPAuE-0.08V). The results exhibited the sensor with a wide linear range (from 1 to 120 mu g L-1) for the simultaneous detection of these three heavy metal ions. Besides, the detection limits of Pb(II), Cd(II), and Zn(II) for the sensor were respectively found to be 0.04 mu g L-1, 0.02 mu g L-1, and 0.05 mu g L-1 (S/N = 3). The proposed sensor revealed good antiinterference ability, satisfactory repeatability with RSDs of less than 2.5% (n = 12), excellent reproducibility with RSDs of less than 2.5% (n = 6), and considerable stability. The detection accuracy of the Bi/SPAuE-0.08V based sensor was further evaluated via atomic absorption spectroscopy (AAS). Due to its simplicity in process, high detection performance and excellent reliability, such sensors are expected to find utility in portable heavy metal detection applications.

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