Target-Induced DNA Mismatch for One-Spot Simultaneous Electrochemical Detection of Multiple Heavy Metals Based on the Amplification of DNA Concatemers
Target-Induced DNA Mismatch for One-Spot Simultaneous Electrochemical Detection of Multiple Heavy Metals Based on the Amplification of DNA Concatemers
复制标题
基于 DNA 串联体扩增的靶标诱导 DNA 错配对多种重金属进行单点同步电化学检测
DOI：
10.1149/2.0041704jes
复制
发表时间：
2017
影响因子：
3.9
通讯作者：
Yuan Yali
中科院分区：
文献类型：
--
作者：
Liu Guangpeng;Wang Jianli;Wang Haijun;Yuan Yali
在这里，我们建立了一种灵敏、选择性地同时检测Ag+和Hg2+的方法，即靶诱导构象切换和DNA串联扩增技术。首次将硫醇标记的富C寡核苷酸(C1)及其部分互补DNA(P1)和硫醇标记的富T寡核苷酸(C2)及其部分互补DNA(P2)共固定在电极上。当引入四条辅助DNA链，即标记LS1和LS2的2-羧酸(AQ)和标记L3和L4的硫氨酸(THI)时，可在电极上形成具有大量AQ和THI部分的扩展双链DNA聚合物，并以P1和P2为引发剂进行串联反应。在Ag+和Hg2+存在下，电极上的C1和C2可以通过插入方式折叠成发夹结构，导致氧化还原标记的DNA串联体从电极上释放出来，氧化还原电流大大降低，用于定量检测靶标。结果表明，在0.0 1~5μM范围内，还原峰电流与被分析物浓度呈良好的线性关系，对Ag+的检出限为2 pm，对Hg2+的检出限为0.5~5 0μM，检出限为7.5 pm。
Here, we develop a sensitive and selective method for simultaneous detection of Ag+ and Hg 2+ by target-induced conformational switch and DNA concatemers amplification protocol. Two dsDNA strands, one is thiol labeled C-rich oligonucleotide (C 1) and its partially complementary DNA (P 1), the other is thiol labeled T-rich oligonucleotide (C 2) and its partially complementary DNA (P 2), were firstly coimmobilized on electrode. When four auxiliary DNA strands, anthraquinone-2-carboxylic acid (AQ) labeled LS 1 and LS 2, thionine (Thi) labeled LS 3 and LS 4, were introduced, extended dsDNA polymers with lots of AQ moieties and Thi moieties could be formed on electrode, which were employed P1 and P2 as primers for concatemer reaction. In the presence of Ag+ and Hg 2+, C 1 and C 2 on electrode via the insertion approach can fold into hairpin structures, resulting in the release of redox-tagged DNA concatemers from electrode with a substantially decreased redox current for quantitatively detecting the targets. As a result, the proposed aptasensor showed a good linear relationship between reduction peak currents and analyte concentrations in the ranges from 0.01 nM to 5 μM with a detection limit of 2 pM for Ag+, and 0.5 nM to 50 μM with a detection limit of 7.5 pM for Hg 2+, respectively.