An ultrasensitive electrochemical method for detection of Ag+ based on cyclic amplification of exonuclease III activity on cytosine-Ag+-cytosine

被引：36

作者：

Xu, Gang ^{[1
]}

Wang, Guangfeng ^{[1
]}

He, Xiuping ^{[1
]}

Zhu, Yanhong ^{[1
]}

Chen, Ling ^{[1
]}

Zhang, Xiaojun ^{[1
]}

机构：

[1] Anhui Normal Univ, Anhui Key Lab Chem Biosensing, Anhui Key Lab Funct Mol Solids, Coll Chem & Mat Sci, Wuhu 241000, Peoples R China

来源：

ANALYST | 2013年 / 138卷 / 22期

基金：

中国国家自然科学基金;

关键词：

ROLLING CIRCLE AMPLIFICATION; DNA DETECTION; SIGNAL AMPLIFICATION; LABEL-FREE; NICKING ENDONUCLEASE; FLUORESCENCE DETECTION; AIDED AMPLIFICATION; NUCLEIC-ACIDS; SILVER; SENSOR;

D O I：

10.1039/c3an01320k

中图分类号：

O65 [分析化学];

学科分类号：

070302 ; 081704 ;

摘要：

Ag+ is known to bind very strongly with cytosine-cytosine (C-C) mismatches in DNA duplexes to form C-Ag+-C base pairs. Exonuclease III (Exo III) can catalyze the stepwise removal of mononucleotides of duplex DNA. In this work, we study Exo III activity on DNA hybrids containing C-Ag+-C base pairs. Our experiments show that Ag+ ions could intentionally trigger the activity of Exo III towards a designed cytosine-rich DNA oligonucleotide (C-rich probe) by the conformational change of the probe. Our sensing strategy uses this conformation-dependent activity of Exo III, which is controlled through the cyclical shuffling of Ag+ ions between the solid DNA hybrid and the solution phase. This interesting conversion has led to the development of an ultrasensitive detection platform for Ag+ ions with a detection limit of 0.03 nM and a total assay time possible within minutes. This simple detection strategy could also be used for the detection of other metal ions which exhibit specific interactions with natural or synthetic bases.

引用

页码：6900 / 6906

页数：7

共 62 条

[1]

[Anonymous], 2003, NUCL ACIDS RES S

[2] IMPEDANCE PLANE DISPLAY FOR AN ELECTRODE WITH DIFFUSION RESTRICTED TO A THIN-LAYER [J].