Oligonucleotide Functionalized Microporous Gold Electrode for the Selective and Sensitive Determination of Mercury by Differential Pulse Adsorptive Stripping Voltammetry (DPAdSV)

• Published in: Analytical letters 2019-12, Vol.52 (18), p.2938-2950
• Main Authors: Yiwei, Xu, Zhihua, Li, Wen, Zhang, Jiyong, Shi, Xiaobo, Zou, Xiaowei, Huang, Xuetao, Hu, Xin, Wang
• Format: Article
• Language: English
• Subjects: Adsorptivity; Chemical reduction; cyclic voltammetry; differential pulse adsorptive stripping voltammetry; Drinking water; Electrodes; Electron transfer; Gold; Ion concentration; Mercury; Mercury (metal); Mercury compounds; Mercury surface; Oligonucleotides; Reproducibility; scanning electron microscopy; Selectivity; Self-assembly; Stripping; Thymine; Voltammetry; X-ray diffraction
• ISSN: 0003-2719; 1532-236X
• DOI: 10.1080/00032719.2019.1631839

A novel electrode modified with oligonucleotide and microporous gold was fabricated for the determination of mercury by differential pulse adsorptive stripping voltammetry (DPAdSV). Microporous gold was synthesized by electrochemical reduction using dynamic hydrogen bubble template. The oligonucleotide was immobilized on microporous gold by self-assembly. The prepared electrode exhibited an improved electrochemical response for mercury(II) ion because of the large surface area and excellent electron transfer capacity provided by microporous gold and the specific coordination between mercury ion and thymine bases in oligonucleotides. Under the optimal experiment conditions, the oligonucleotide functionalized microporous gold electrode had a linear relationship between the stripping current and mercury ion concentration in the range from 0.5 to 30 µg/L with a detection limit of 0.021 µg/L. Moreover, the prepared electrode exhibited good selectivity, reproducibility, repeatability and stability. Furthermore, the prepared electrode was applied to detect mercury in tap water with satisfactory results.