Competitive aptamer bioassay for selective detection of adenosine triphosphate based on metal-paired molecular conformational switch and fluorescent gold nanoclusters

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• 作者：Jing-Min Liu ; Xiu-Ping Yan ; ^{xpyan@nankai.edu.cn}
• 关键词：Molecule beacon ; Aptamer ; Adenosine triphosphate ; Gold nanoclusters ; Competitive bioassay
• 刊名：Biosensors and Bioelectronics
• 出版年：2012
• 期刊代码：12_09565663
• 类别：ch
• 出版时间：June-July, 2012
• 卷：36
• 期：1
• 页码：135-141
• 文件大小：863 K

摘要

A competitive aptamer bioassay was developed for the selective detection of adenosine triphosphate (ATP). The proposed bioassay employed the T-Hg-T induced hairpin-structure as the molecule conformational switch (MCS), aptamer as a specific recognizer, and mercaptoundecanoic acid modified gold nanoclusters (MUA-AuNCs) as a sensitive signal reporter. The T-rich MCS ssDNA with the sequence complementary with that for the aptamer of ATP was bound with Hg²⁺ to form the metal-paired hairpin-structure. Addition of the aptamer and its target biomolecule ATP resulted in a competitive aptamer bioassay. The aptamer competed with Hg²⁺ to hybridize with T-rich MCS ssDNA, thereby destroyed the hairpin-structure. As a result, the Hg²⁺ was released and the signal transduction was achieved. The ATP affected the interaction between aptamer and hairpin-structure, thus mediated the release of Hg²⁺, which was sensitively quantified by fluorescent MUA-AuNCs. Under selected conditions, the developed method allowed sensitive and selective detection of ATP with a linear range of 100-2000 nM and a detection limit (3s) of 48 nM. The relative standard deviation for sixty replicate detections of 200 nM ATP was 2.1%, and the recoveries of the spiked ATP in urine samples ranged from 89%to 105%. The developed metal-paired MCS can be easily extended to the sensitive and selective detection of other biomolecules by changing the base sequence of hairpin structure and choosing the corresponding aptamer for the target biomolecule.