Department of Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190, Thailand.
National Nanotechnology, National Science and Technology Development Agency, Pathum Thani, 12120, Thailand.
Talanta. 2021 Jan 1;221:121669. doi: 10.1016/j.talanta.2020.121669. Epub 2020 Sep 15.
Mercury ion (Hg) is considered to be one of the most toxic heavy metal ions and can cause adverse effects on kidney function, the central nervous system, and the immune system. Therefore, it is important to develop a fast and simple method for sensitive and selective detection of Hg in the environment. This research proposes a portable electrochemical sensor for rapid and selective detection of Hg. The sensor platform is designed based on thymine acetic acid anchored with cysteamine-conjugated core shell FeO@Au nanoparticles (FeO@Au/CA/T-COOH) immobilized on a sensing area of a screen-printed carbon electrode (SPCE) with the aid of an external magnetic field embedded in a homemade electrode holder for ease of handling. In the presence of Hg, the immobilized thymine combines specifically with Hg and forms a thymine-Hg-thymine mismatch (T-Hg-T). The resulting amount of Hg was determined by differential pulse anodic stripping voltammetry (DPASV). Under optimal conditions, the sensor exhibited two wide linearities in a range from 1 to 200 μg L and 200-2200 μg L with the reliability coefficient of determination of 0.997 and 0.999, respectively. The detection limit (LOD) and the quantification limit (LOQ) were also determined to be 0.5 μg L and 1.0 μg L, respectively. The sensor was further applied for determination of Hg in water samples, a certified reference material and fish samples. The results were compared with flow injection atomic spectroscopy-inductively coupled plasma-optical emission spectroscopy (FIAS-ICP-OES) systems as a reference method. Results obtained with the proposed sensor were relatively satisfactory, and they showed no significant differences at a 95% confidence level by t-test from the standard method. Therefore, considering its fast and simple advantages, this novel strategy provides a potential platform for construction of a Hg electrochemical sensor.
汞离子（Hg）被认为是最具毒性的重金属离子之一，可对肾功能、中枢神经系统和免疫系统造成不良影响。因此，开发一种快速、简单的方法来灵敏、选择性地检测环境中的 Hg 离子至关重要。本研究提出了一种用于快速、选择性检测 Hg 的便携式电化学传感器。该传感器平台是基于胸腺嘧啶乙酸与巯基乙胺偶联的核壳型 FeO@Au 纳米粒子（FeO@Au/CA/T-COOH）设计的，将其固定在丝网印刷碳电极（SPCE）的传感区域上，同时借助于内置在自制电极支架中的外部磁场，方便操作。在 Hg 存在的情况下，固定的胸腺嘧啶特异性地与 Hg 结合，形成胸腺嘧啶-Hg-胸腺嘧啶错配（T-Hg-T）。通过差分脉冲阳极溶出伏安法（DPASV）测定形成的 Hg 量。在最佳条件下，传感器在 1 至 200μg/L 和 200 至 2200μg/L 的范围内呈现出两条宽线性，其可靠性系数的决定分别为 0.997 和 0.999。检测限（LOD）和定量限（LOQ）也分别确定为 0.5μg/L 和 1.0μg/L。该传感器还进一步用于水样、标准参考物质和鱼样中 Hg 的测定。结果与作为参考方法的流动注射原子光谱-电感耦合等离子体-光学发射光谱（FIAS-ICP-OES）系统进行了比较。通过 t 检验，与标准方法相比，所提出的传感器的结果相对令人满意，在 95%置信水平下没有显著差异。因此，考虑到其快速、简单的优势，这种新策略为构建 Hg 电化学传感器提供了一个潜在的平台。
