Selective detection of mercury(II) and methylmercury(II) via coordination-induced emission of a small-molecule probe

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• 作者：Yan Yang ; Zhiyi Yao ; Wei Li ; Kui Chen ; Lei Liu ; Hai-Chen Wu
• 关键词：mercury ; methylmercury ; coordination ; induced emission ; fluorescence enhancement ; selectivity
• 刊名：Science China Chemistry
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：59
• 期：12
• 页码：1651-1657
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry/Food Science, general;
• 出版者：Science China Press
• ISSN：1869-1870
• 卷排序：59

文摘

Mercury is one of the major toxic pollutants and has many adverse effects on human health. The main mercury species in the environment or in living organisms are inorganic mercuric ion (Hg2+) and organic methylmercury (CH3Hg+). Detection of the two mercury ions is a particularly active topic in the molecular sensing field during the past decade. However, efficient sensors that can sensitively detect and discriminate the two species are rare. In this work, we adopt the concept of restriction of intramolecular rotations which is the basis of aggregation induced emission, and design a molecular probe with pyridyl group as the chelating unit and 1,8-naphthalimide as the fluorescent unit for the detection of both Hg2+ and CH₃Hg+. When the probe is free in solution, it exhibits weak fluorescence because free intramolecular rotations of the 1,8-naphthalimide moieties non-radiatively annihilate its excited state. However, upon coordination with Hg2+ or CH₃Hg+, the rotation of 1,8-naphthalimide moieties would be restricted due to the chelation between 1,8-naphthalimide and Hg2+ or CH₃Hg+, leading to significantly enhanced fluorescent emission. The response induced by Hg2+ is much stronger than CH₃Hg+; but for specific detection of CH₃Hg+, we introduced a T-rich DNA fragment which could completely mask Hg2+ in solution. Furthermore, we have employed the sensor for confocal imaging of Hg2+ and CH₃Hg+in immobilized cells. We expect the probe design tactics can be generally useful for sensing many other analytes.