A label-free biosensor for DNA detection based on ligand-responsive G-quadruplex formation
A label-free biosensor for DNA detection based on ligand-responsive G-quadruplex formation
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DOI：
10.1016/j.talanta.2013.04.003
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发表时间：
2013-09-30
期刊：
影响因子：
6.1
通讯作者：
Hu, Jiming
中科院分区：
文献类型：
--
作者：
Guo, Yahui;Xu, Pei;Hu, Jiming
利用无标记分子信标和荧光染料N-甲基中卟啉IX（NMM）建立了一种简便、无标记的单链DNA序列检测方法。以人免疫缺陷病毒（HIV）RNA片段的逆转录寡核苷酸序列（靶DNA，20个碱基）为模型系统进行了验证。在没有靶DNA存在的情况下，MBs以茎闭合形式存在，不能形成G-四链体结构，NMM的荧光信号很低。在靶DNA存在下，MBs由“Off”变为“On”，从而促进了G-四链体的形成，从而大大增强了NMM的荧光。该生物传感器设计简单、操作快速，比其他方法更方便、更有应用前景。该方法的检测限为1.4 nM，检测时间小于30 min。不需要复杂的实验技术或DNA序列的化学修饰。这种新方法可广泛应用于灵敏和选择性的核酸检测。(C)2013爱思唯尔有限公司版权所有。
A facile and label-free assay with label-free molecular beacons (MBs) and fluorescent dye N-methyl mesoporphyrin IX (NMM) was developed for the detection of specific single-stranded DNA sequences. It was demonstrated by a reverse transcription oligonucleotide sequence (target DNA, 20 bases) of RNA fragment of human immunodeficiency virus (HIV) as model systems. In the absence of target DNA, the MBs were in the stem-closed form, the G-quadruplex structure could not form and the fluorescence signal of NMM was very low. In the presence of target DNA the MBs turned "Off" to "On", thus promoting the formation of G-quadruplex which could greatly enhance the fluorescence of NMM. This biosensor was simple in design, fast in operation, and more convenient and promising than other methods. It took less than 30 min to finish and its detection limit was 1.4 nM. No sophisticated experimental techniques or chemical modification for DNA sequences were required. This new approach could be widely applied to sensitive and selective nucleic acids detection. (C) 2013 Elsevier B.V. All rights reserved.