Kim Kyung Min, Nam Yun-Sik, Lee Yeonhee, Lee Kang-Bong
Green City Technology Institute, Korea Institute of Science and Technology, Hwarang-ro 14 gil 5, Seoul 02792, Republic of Korea.
Department of Chemistry, Korea University, Anam-ro, Seongbuk-gu, P.O. Box 145, Seoul 136-701, Republic of Korea.
J Anal Methods Chem. 2018 Feb 5;2018:1206913. doi: 10.1155/2018/1206913. eCollection 2018.
A highly sensitive and selective colorimetric assay for the detection of Hg ions was developed using gold nanoparticles (AuNPs) conjugated with polyethyleneimine (PEI). The Hg ion coordinates with PEI, decreasing the interparticle distance and inducing aggregation. Time-of-flight secondary ion mass spectrometry showed that the Hg ion was bound to the nitrogen atoms of the PEI in a bidentate manner (N-Hg-N), which resulted in a significant color change from light red to violet due to aggregation. Using this PEI-AuNP probe, determination of Hg ion can be achieved by the naked eye and spectrophotometric methods. Pronounced color change of the PEI-AuNPs in the presence of Hg was optimized at pH 7.0, 50°C, and 300 mM·NaCl concentration. The absorption intensity ratio (/) was correlated with the Hg concentration in the linear range of 0.003-5.0 M. The limits of detection were measured to be 1.72, 1.80, 2.00, and 1.95 nM for tap water, pond water, tuna fish, and bovine serum, respectively. Owing to its facile and sensitive nature, this assay method for Hg ions can be applied to the analysis of water and biological samples.
使用与聚乙烯亚胺（PEI）共轭的金纳米颗粒（AuNPs）开发了一种用于检测汞离子的高灵敏度和选择性比色测定法。汞离子与PEI配位，减小颗粒间距离并诱导聚集。飞行时间二次离子质谱表明，汞离子以双齿方式（N-Hg-N）与PEI的氮原子结合，由于聚集导致颜色从浅红色显著变为紫色。使用这种PEI-AuNP探针，可以通过肉眼和分光光度法测定汞离子。在pH 7.0、50°C和300 mM·NaCl浓度下优化了在汞存在下PEI-AuNPs的明显颜色变化。吸收强度比（/）在0.003-5.0 M的线性范围内与汞浓度相关。自来水、池塘水、金枪鱼和牛血清的检测限分别测定为1.72、1.80、2.00和1.95 nM。由于其简便和灵敏的性质，这种汞离子测定方法可应用于水和生物样品的分析。
