基于对硫黄素T诱导的DNA G-四链体抑制作用检测银离子  

Determination of Silver Ion Based on Inhibiting DNA G-quadruplexes Induced by Thioflavin T

作　　者：刘毅 彭丽华 任昀 

机构地区：[1]湖南省计量检测研究院,湖南长沙410014

出　　处：《分析测试学报》2015年第3期352-356,共5页Journal of Instrumental Analysis

基　　金：质检公益性行业科研专项"双打"项目(2012104001);国家科技支撑计划项目(2013BAK12B06);湖南省科学技术厅科研条件创新专项(2013TT2033)

摘　　要：发展了基于DNA探针的新型银离子免标记检测方法.富含C和G碱基的DNA序列可在荧光染料硫黄素T（ThT）的诱导下折叠形成四链体结构,并使ThT的荧光显著增强,但该ThT—DNA复合形成的四链体易被银离子破坏.依据此特性,设计了一种新型的免标记银离子传感器.银离子的响应范围为0.1 ～10μmol/L,检出限为60 nmol/L,具有较高的灵敏度.该方法已成功应用于湘江水和自来水样品中银离子的检测,结果表明ThT—DNA复合四链体有望提供一种可靠、高灵敏和特异的检测平台,实现复杂体系中银离子的定量分析.A new label-free method for the detection of Ag ＋ was developed. The G-rich DNA se- quences with many C loop residues can be folded into quadruplex structures with thioflavin T（ThT） as inducer, but this quadruplex structure can be destroyed by Ag ＋ ions, thus a novel label-free biosen- sot was designed based on this principle. A detection limit as low as 60 nmol/L and a wide dynamatic range of 0. 1 -10 μmol/L were achieved in this assay. The method was applied in the detection of silver ions in samples from Xiangjiang water and tap water with satisfactory results. In view of these advantages, the developed method was expected to provide an intrinsically robust, highly sensitive and specific sensing platform for the analysis of Ag＋ in complex system.

关 键 词：G-四链体 银离子(Ag+) 硫黄素T(ThT) 传感器 

分 类 号：O561.3[理学—原子与分子物理] O614.122[理学—物理]