MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China.
Biosens Bioelectron. 2010 Oct 15;26(2):859-62. doi: 10.1016/j.bios.2010.07.098. Epub 2010 Aug 1.
A novel and highly sensitive electrochemiluminescence (ECL) assay based on magnetic beads separation/collection process and thymine-Hg2+-thymine (T-Hg2+-T) coordination chemistry has been designed to detect Hg2+ ions in aqueous solution. In this protocol, two amine-terminated complementary DNA probes with five thymine-thymine (T-T) mismatches were introduced. One was coupled with carboxyl-modified magnetic beads and the other was labeled with tris (2, 2-bipyridine) ruthenium (II) (TBR). The couple of DNA probes, in the presence of Hg2+, can form double-stranded structure via the Hg2+-mediated coordination of T-Hg2+-T base pair. Therefore, they can be collected on the surface of electrode using a magnetic field. On the electrode, TBR labels and tripropylamine (TPA) could react to emit photons, which were detected by a custom-built ECL system. The detection limit for Hg2+ in this assay is 5 nM, which is below the upper limit of Hg2+ for drinkable water mandated by United States Environmental Protection Agency (EPA), 10 nM. To the best of our knowledge, this is the first example of ECL assay applying to detect Hg2+ with highly sensitivity and selectivity.
基于磁珠分离/收集过程和胸腺嘧啶-汞 2+-胸腺嘧啶（T-Hg 2+-T）配位化学，设计了一种新颖且高灵敏度的电化学发光（ECL）测定法，用于检测水溶液中的 Hg 2+离子。在该方案中，引入了两条带有五个胸腺嘧啶-胸腺嘧啶（T-T）错配的氨基末端互补 DNA 探针。一条与羧基修饰的磁珠偶联，另一条用三（2,2-联吡啶）钌（II）（TBR）标记。在存在 Hg 2+的情况下，这些 DNA 探针可以通过 Hg 2+-介导的 T-Hg 2+-T 碱基对配位形成双链结构。因此，它们可以使用磁场收集在电极表面上。在电极上，TBR 标记物和三丙胺（TPA）可以反应发射光子，这些光子可以通过定制的 ECL 系统进行检测。该测定法检测 Hg 2+的检出限为 5 nM，低于美国环境保护署（EPA）规定的饮用水中 Hg 2+的上限 10 nM。据我们所知，这是首次应用 ECL 测定法以高灵敏度和选择性检测 Hg 2+的实例。
