高等学校化学学报

高等学校化学学报 ›› 2012, Vol. 33 ›› Issue (12): 2651.doi: 10.7503/cjcu20120358

• 分析化学 • 上一篇    下一篇

基于T-Hg2+-T及G四聚体自身熄灭能力的“Turnon”型单标记DNA荧光探针用于碘离子的检测

朱颖, 刘沛, 羊小海, 何磊良, 李清照, 王青, 王柯敏, 黄晋, 刘剑波   

  1. 湖南大学化学生物传感与计量学国家重点实验室, 化学化工学院, 生物纳米与分子工程湖南省重点实验室, 长沙 410082
  • 收稿日期:2012-04-16 出版日期:2012-12-10 发布日期:2012-11-20
  • 通讯作者: 王柯敏,男,博士,教授,博士生导师,主要从事纳米及分子水平上的生物分析化学及纳米生物研究.E-mail:kmwang@hnu.edu.cn E-mail:kmwang@hnu.edu.cn;yangxiaohai@hnu.edu.cn
  • 基金资助:

    国家自然科学基金(批准号: 91027000, 20805012)、 科技部国际合作重大项目(批准号: 2010DFB30300)和教育部"新世纪优秀人才支持计划"(批准号: NCET-09-0338)资助.

Single-labeled“Turn on” Fluorescent Oligonucleotide Probe for Iodide Detection Based on T-Hg2+-T and Inherent Quenching Ability of G-quadruplex

ZHU Ying, LIU Pei, YANG Xiao-Hai, HE Lei-Liang, LI Qing-Zhao, WANG Qing, WANG Ke-Min, HUANG Jin, LIU Jian-Bo   

  1. State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University, Changsha 410082, China
  • Received:2012-04-16 Online:2012-12-10 Published:2012-11-20
  • Contact: Kemin Wang E-mail:kmwang@hnu.edu.cn;yangxiaohai@hnu.edu.cn

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摘要：

利用G四聚体可以熄灭荧光的特性以及T-Hg2+-T的特殊结构, 发展了一种简便的"Turn on"型碘离子检测新方法. 设计了一条5'端标有荧光基团的富T序列, 3'端采用能形成G四聚体的富G序列代替传统的熄灭基团. 加入汞离子后, 富T序列形成T-Hg2+-T机构发生折叠, G四聚体靠近荧光基团, 发生光诱导电子转移, 使荧光被熄灭. 若加入碘离子, 碘离子会与汞离子形成较稳定的配合物, 汞离子从DNA上被竞争下来, 探针的荧光得以恢复, 且荧光强度与50～500 nmol/L的碘离子呈良好线性关系, 检出限为30 nmol/L. 本方法选择性好, 10倍于碘离子浓度的其它常见阴离子干扰较小. 检测自来水样中碘离子的回收率为92%～109%, 相对标准偏差RSD<4%(n=4).

关键词: 碘离子, 荧光, DNA探针, G四聚体

Abstract:

A simple and "Turn on" type iodide anion assay method was developed, based on the inherent quenching ability of G-quadruplex and fidelity of the "thymine-Hg2+-thymine" binding motif. A T-rich sequence was labeled with 6-carboxyfluorescein(FAM) at its 5'-end, nearby the 3'-end was a G-rich sequence which could form G-quadruplex structure instead of traditional quenchers. Upon addition of Hg2+, T-rich sequence folded into a hairpin structure which led the G-quadruplex near to the FAM, and the FAM was quenched by the G-quadruplex owning to photoinduced electron transfer between the dye and the G-quadruplex. After the addition of iodide, the fluorescence of FAM recovered considering that iodide could bind with Hg2+. The novel method for the determination of iodide was developed in linear range of 50—500 nmol/L, with the detection limit(3σ) of 30 nmol/L. This proposed method was highly selective and other anions have no interfering effects on the determination, which was successfully applied for analysis of real samples with the recovery from 92%—109%, and the RSD<4%(n=4).

Key words: Iodide, Fluorescence, DNA probe, G-quadruplex

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