Key Laboratory of Eco-chemical Engineering, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, China.
Biosens Bioelectron. 2010 Feb 15;25(6):1338-43. doi: 10.1016/j.bios.2009.10.023. Epub 2009 Oct 27.
A novel "signal-on" assay for sensitive and selective detection of Hg(2+) in aqueous solution based on mismatched DNA and a molecular light switch complex, Ru(phen)(2)(dppz), was reported in the present work. This Hg(2+) specific sensor system composed of two label-free DNA probes with eight T-T mismatches, which could form stable DNA duplexes by thymine-Hg(2+)-thymine (T-Hg(2+)-T) in the presence of Hg(2+). The luminescence of Ru(phen)(2)(dppz) is very weak in aqueous solution, and significant luminescence can be observed when intercalating into DNA duplexes. By monitoring Hg(2+)-dependent luminescence intensity enhancement, highly sensitive and selective determination of Hg(2+) has been achieved. Under the optimum conditions, the luminescence intensity was proportional to the concentration of Hg(2+) in the range of 1.0x10(-9)-1.5x10(-7) M. A detection limit of 3.5x10(-10) M Hg(2+) was achieved using 3sigma. The presence of other metal ions did not interfere with the detection of Hg(2+) even at high concentrations. This approach is simple and rapid, which can be used to monitor the Hg(2+) concentration in drinking water and natural media within 30 min.
本工作报道了一种基于错配 DNA 和分子光开关配合物 Ru(phen)(2)(dppz) 的新型“信号开启”用于水溶液中 Hg(2+)的灵敏和选择性检测的分析方法。该 Hg(2+)特异性传感器系统由两条无标记 DNA 探针组成，这些探针带有 8 个 T-T 错配，可以在存在 Hg(2+)的情况下通过胸腺嘧啶-Hg(2+)-胸腺嘧啶 (T-Hg(2+)-T) 形成稳定的 DNA 双链。Ru(phen)(2)(dppz)在水溶液中的荧光很弱，而当嵌入 DNA 双链时可以观察到显著的荧光。通过监测 Hg(2+)依赖性的荧光强度增强，可以实现对 Hg(2+)的高灵敏度和选择性测定。在最佳条件下，荧光强度与 Hg(2+)的浓度在 1.0x10(-9)-1.5x10(-7) M 范围内呈正比。使用 3sigma 检测到的 Hg(2+)的检出限为 3.5x10(-10) M。即使在高浓度下，其他金属离子的存在也不会干扰对 Hg(2+)的检测。该方法简单快速，可用于在 30 分钟内监测饮用水和自然介质中的 Hg(2+)浓度。
