Label-Free and Enzyme-Free Colorimetric Detection of Pb2+ Based on RNA Cleavage and Annealing-Accelerated Hybridization Chain Reaction
Label-Free and Enzyme-Free Colorimetric Detection of Pb2+ Based on RNA Cleavage and Annealing-Accelerated Hybridization Chain Reaction
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基于 RNA 切割和退火加速杂交链式反应的 Pb2 无标记和无酶比色检测
DOI：
10.1021/acs.analchem.9b00410
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发表时间：
2019-04-02
影响因子：
7.4
通讯作者：
Duan, Yixiang
中科院分区：
文献类型：
--
作者：
Huang, Zhijun;Chen, Junman;Duan, Yixiang
报道了一种用于快速检测 Pb2+ 的无标记、无酶比色传感器，该传感器基于 DNAzyme 介导的 RNA 裂解与退火加速 DNA 杂交链式反应 (HCR) 相结合的策略。 DNAzyme的底物链(S-TM)作为触发DNA，可以有效启动HCR。然而，当它在 Pb2+ 存在的情况下被 DNAzyme 切割时，DNA 功能域的分离导致 HCR 效率严重下降。结果，Pb2+浓度的差异转化为DNA组装的差异，最终导致胶体金纳米粒子（AuNPs）的颜色变化。在这项工作中，利用与DNAzyme的催化链(GR5)完全互补的DNA链(cGR5)来改善S-TM的解离，以提高HCR效率。此外，首次利用DNA退火的简单操作来加速HCR过程，使得Pb2+检测在约30分钟内完成。由于具有灵敏度高、选择性好、抗干扰能力强、实用性能好等优点，预计这种廉价、简单的比色传感器将有助于环境和食品样品的现场检测。
A label-free and enzyme-free colorimetric sensor for rapid detection of Pb2+ is reported, which is based on the strategy of DNAzyme-mediated RNA cleavage combined with an annealing-accelerated DNA hybridization chain reaction (HCR). As a trigger DNA, the substrate strand (S-TM) of DNAzyme can initiate HCR effectively. However, when it is cleaved by DNAzyme in the presence of Pb2+, the separation of DNA functional domains leads to a serious decrease in HCR efficiency. As a result, the difference in Pb2+ concentration converts into the difference of DNA assembly, which eventually leads to the color change of colloidal gold nanoparticles (AuNPs). In this work, a DNA strand (cGR5) completely complementary to the catalytic strand (GR5) of DNAzyme is used to improve the dissociation of S-TM to enhance the HCR efficiency. In addition, the simple operation of DNA annealing is first used to accelerate the HCR process, enabling the Pb2+ detection to be completed in about 30 min. As advantages of high sensitivity, good selectivity, strong anti-interference ability, and good practical performance are achieved, it is anticipated that the cheap and simple colorimetric sensor will be helpful for on-site detection of environmental and food samples.