Han Mingjie, Xie Yong, Wang Ri, Li Yang, Bian Chao, Xia Shanhong
State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China.
School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100190, China.
Micromachines (Basel). 2023 Mar 27;14(4):739. doi: 10.3390/mi14040739.
As a highly toxic heavy metal ion, mercury ion (Hg) pollution has caused serious harm to the environment and human health. In this paper, 4-mercaptopyridine (4-MPY) was selected as the sensing material and decorated on the surface of a gold electrode. Trace Hg could be detected by both differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) methods. The proposed sensor displayed a wide detection range from 0.01 μg/L to 500 μg/L with a low limit of detection (LOD) of 0.002 μg/L by EIS measurements. Combined with molecular simulations and electrochemical analyses, the chelating mechanism between Hg and 4-MPY was explored. Through the analysis of binding energy (BE) values and stability constants, 4-MPY showed an excellent selectivity for Hg. In the presence of Hg, the coordination of Hg with the pyridine nitrogen of 4-MPY was generated at the sensing region, which caused a change in the electrochemical activity of the electrode surface. Due to the strong specific binding capability, the proposed sensor featured excellent selectivity and an anti-interference capability. Furthermore, the practicality of the sensor for Hg detection was validated with the samples of tap water and pond water, which demonstrated its potential application for on-site environmental detection.
汞离子（Hg）作为一种剧毒重金属离子，其污染已对环境和人类健康造成了严重危害。本文选用4-巯基吡啶（4-MPY）作为传感材料并修饰在金电极表面。痕量Hg可通过差分脉冲伏安法（DPV）和电化学阻抗谱（EIS）两种方法进行检测。所提出的传感器通过EIS测量显示出0.01 μg/L至500 μg/L的宽检测范围，检测限低至0.002 μg/L。结合分子模拟和电化学分析，探究了Hg与4-MPY之间的螯合机理。通过对结合能（BE）值和稳定常数的分析，4-MPY对Hg表现出优异的选择性。在有Hg存在的情况下，Hg与4-MPY的吡啶氮在传感区域发生配位，导致电极表面的电化学活性发生变化。由于具有强特异性结合能力，所提出的传感器具有优异的选择性和抗干扰能力。此外，通过自来水和池塘水样品验证了该传感器用于Hg检测的实用性，证明了其在现场环境检测中的潜在应用价值。
