Department of Dermatology, Guangzhou Institute of Dermatology, Guangzhou 510095, China.
Biosens Bioelectron. 2011 Jul 15;26(11):4464-70. doi: 10.1016/j.bios.2011.05.003. Epub 2011 May 11.
We report a sensitive method for visual detection of mercury ions (II) (Hg²⁺) in aqueous solution by using gold nanoparticles (Au-NPs) and thymine (T)-rich hairpin DNA probes. The thiolated hairpin DNA probe was immobilized on the Au-NP surface through a self-assembling method. Another thymine-rich, digoxin-labeled DNA probe was introduced to form DNA duplexes on the Au-NP surface with thymine-Hg²⁺-thymine (T-Hg²⁺-T) coordination in the presence of Hg²⁺. The Au-NPs associated with the formed duplexes were captured on the test zone of a lateral flow strip biocomponent (LFSB) by immunoreaction events between the digoxin on the duplexes and anti-digoxin antibodies on the LFSB. The accumulation of Au-NPs produced a characteristic red band on the test zone, enabling visual detection of Hg²⁺ without instrumentation. A detection limit of 0.1 nM was obtained under optimal experimental conditions. This method provides a simple, rapid, sensitive approach for the detection of Hg²⁺ and shows great promise for point-of-care and in-field detection of environmentally toxic mercury.
我们报告了一种在水溶液中通过使用金纳米粒子（Au-NPs）和富含胸腺嘧啶（T）的发夹 DNA 探针来可视化检测汞离子（II）（Hg²⁺）的灵敏方法。巯基化的发夹 DNA 探针通过自组装方法固定在 Au-NP 表面上。另一个富含胸腺嘧啶、地高辛标记的 DNA 探针被引入到 Au-NP 表面上，形成 DNA 双链体，在存在 Hg²⁺的情况下，通过胸腺嘧啶-Hg²⁺-胸腺嘧啶（T-Hg²⁺-T）配位。与形成的双链体相关的 Au-NPs 通过双链体上的地高辛与 LFSB 上的抗地高辛抗体之间的免疫反应事件被捕获在横向流动条生物元件（LFSB）的测试区域上。Au-NPs 的积累在测试区域产生了一个特征性的红色条带，无需仪器即可实现 Hg²⁺的可视化检测。在最佳实验条件下，得到了 0.1 nM 的检测限。该方法为 Hg²⁺的检测提供了一种简单、快速、灵敏的方法，有望用于环境有毒汞的现场即时检测。
