Hairpin DNA probe with 5¡ä-TCC/CCC-3¡ä overhangs for the creation of silver nanoclusters and miRNA assay

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• 作者：Xiaodong Xia ; Yuanqiang Hao ; Shengqiang Hu ; Jianxiu Wang
• 关键词：Hairpin DNA probe ; Silver nanoclusters ; Fluorescence quenching ; Target miRNA
• 刊名：Biosensors and Bioelectronics
• 出版年：2014
• 出版时间：15 January, 2014
• 年：2014
• 卷：51
• 期：Complete
• 页码：36-39
• 全文大小：662 K

文摘

A facile strategy for the assay of target miRNA using fluorescent silver nanoclusters (AgNCs) has been described. Due to the preferable interaction between cytosine residues and Ag⁺, a short cytosine-rich oligonucleotide (ODN) with only six bases 5¡ä-TCCCCC-3¡ä served as an efficient scaffold for the creation of the AgNCs. The AgNCs displayed a bright red emission when excited at 545 nm. Such ODN base-stabilized AgNCs have been exploited for miRNA sensing. Overhangs of TCC at the 5¡ä end (5¡ä-TCC) and CCC at the 3¡ä end (CCC-3¡ä) (denoted as 5¡ä-TCC/CCC-3¡ä) appended to the hairpin ODN probe which also contains recognition sequences for target miRNA were included. Interestingly, the AgNCs/hairpin ODN probe showed similar spectral properties as that templated by 5¡ä-TCCCCC-3¡ä. The formation of the hairpin ODN probe/miRNA duplex separated the 5¡ä-TCC/CCC-3¡ä overhangs, thus disturbing the optical property or structure of the AgNCs. As a result, fluorescence quenching of the AgNCs/hairpin ODN probe was obtained, which allows for facile determination of target miRNA. The proposed method is simple and cost-effective, holding great promise for clinical applications.