College of Materials Science & Engineering, South China University of Technology, Guangzhou 510640, China.
Langmuir. 2010 Nov 16;26(22):17764-71. doi: 10.1021/la103368z. Epub 2010 Oct 19.
The selective and sensitive detection methods for toxic transition-metal ions, which are rapid, facile, and applicable to the environmental and biological milieus, are of great importance. In this study, we designed a β-CD-based ratiometric sensor for detecting mercury ions in aqueous media, some biological fluids, and live cells. In this sensing platform, the thiocarbamido-containing probe dye was covalently linked onto the hydrophilic β-CD rim, which is conducive to complexing with metal ion, while the donor dye was anchored inside hydrophobic β-CD cavity via the adamantyl moiety, which is good for avoiding self-aggregation and enhancing the quantum yield of the donor dye. Upon associating with mercury ion, the probe dye undergoes ring-opening process and serves as the energy acceptor and constitutes the FRET system with the donor dye; by this way ratiometric detection of mercury ion in water can be realized with the detection limit of 10 nM. The cyclodextrin plays a crucial role for the sensing system; it not only accommodates both the donor dye and the probe dye which can form FRET system upon addition of Hg(2+) but also makes the sensor water-soluble and cell membrane permeable. This nontoxic sensing platform can be used for mercury ion detection in aqueous medium, biological fluids, and live cells (L929 and Hela). We also found that, upon being taken up by L929 cells, the sensor exhibited no cytotoxicity, and the cell proliferation was not affected.
用于检测有毒过渡金属离子的选择性和灵敏性方法，这些方法应具有快速、简便且适用于环境和生物环境的特点，这一点非常重要。在本研究中，我们设计了一种基于β-环糊精的比率型传感器，用于在水介质、一些生物流体和活细胞中检测汞离子。在这个传感平台中，含硫代氨基甲酰基的探针染料通过共价键连接到亲水性的β-环糊精边缘，这有利于与金属离子络合，而供体染料通过金刚烷基部分锚定在疏水性的β-环糊精腔内，这有利于避免自聚集并增强供体染料的量子产率。与汞离子结合后，探针染料经历开环过程，并作为能量受体，与供体染料构成 FRET 体系；通过这种方式，可以在水中实现对汞离子的比率检测，检测限为 10 nM。环糊精对传感系统起着至关重要的作用；它不仅容纳了供体染料和探针染料，当加入 Hg(2+)时可以形成 FRET 体系，而且还使传感器水溶性和细胞膜通透性。这个无毒的传感平台可以用于检测水介质、生物流体和活细胞（L929 和 Hela）中的汞离子。我们还发现，当被 L929 细胞摄取时，传感器没有表现出细胞毒性，细胞增殖也没有受到影响。
