Label-free aptamer-based colorimetric detection of mercury ions in aqueous media using unmodified gold nanoparticles as colorimetric probe
Label-free aptamer-based colorimetric detection of mercury ions in aqueous media using unmodified gold nanoparticles as colorimetric probe
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DOI：
10.1007/s00216-009-2640-0
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发表时间：
2009-04-01
影响因子：
4.3
通讯作者：
Jin, Yan
中科院分区：
文献类型：
--
作者：
Li, Li;Li, Baoxin;Jin, Yan
我们报告了一种简单而灵敏的基于适体的汞离子 (Hg2+) 比色检测，使用未修饰的金纳米颗粒作为比色探针。它基于这样的事实：裸露的金纳米颗粒与短单链 DNA 和双链 DNA 的相互作用不同。抗Hg2+适体富含胸腺嘧啶(T)，在Hg2+存在下很容易形成T-Hg2+-T构型。通过测量颜色变化或吸附率，裸露的金纳米粒子可以有效地区分在给定高浓度盐存在下Hg2+诱导的适体构象变化。该测定显示在 1 x 10(-4) mol L-1 至 1 x 10(-9) mol L-1 的五个十年范围内对 Hg2+ 浓度的线性响应。即使用肉眼，我们也可以在几分钟内识别出微摩尔级的 Hg2+ 浓度。通过使用光谱法，检测限提高到纳摩尔范围（0.6 nM）。该测定对 Hg2+ 的选择性优于其他金属阳离子，包括 K+、Ba2+、Ni2+、Pb2+、Cu2+、Cd2+、Mg2+、Ca2+、Zn2+、Al3+ 和 Fe3+。这种 Hg2+ 测定的主要优点是水溶性、简单、成本低、目视比色法和高灵敏度。该方法为 Hg2+ 检测提供了潜在有用的工具。
We report a simple and sensitive aptamer-based colorimetric detection of mercury ions (Hg2+) using unmodified gold nanoparticles as colorimetric probe. It is based on the fact that bare gold nanoparticles interact differently with short single-strand DNA and double-stranded DNA. The anti-Hg2+ aptamer is rich in thymine (T) and readily forms T-Hg2+-T configuration in the presence of Hg2+. By measuring color change or adsorption ratio, the bare gold nanoparticles can effectively differentiate the Hg2+-induced conformational change of the aptamer in the presence of a given salt with high concentration. The assay shows a linear response toward Hg2+ concentration through a five-decade range of 1 x 10(-4) mol L-1 to 1 x 10(-9) mol L-1. Even with the naked eye, we could identify micromolar Hg2+ concentrations within minutes. By using the spectrometric method, the detection limit was improved to the nanomolar range (0.6 nM). The assay shows excellent selectivity for Hg2+ over other metal cations including K+, Ba2+, Ni2+, Pb2+, Cu2+, Cd2+, Mg2+, Ca2+, Zn2+, Al3+, and Fe3+. The major advantages of this Hg2+ assay are its water-solubility, simplicity, low cost, visual colorimetry, and high sensitivity. This method provides a potentially useful tool for the Hg2+ detection.