Sequence-specific detection of trace DNA via a junction-probe electrochemical sensor employed template-enhanced hybridization strategy.
Sequence-specific detection of trace DNA via a junction-probe electrochemical sensor employed template-enhanced hybridization strategy.
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DOI：
10.1016/j.bios.2009.08.032
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发表时间：
2009-12
影响因子：
12.6
通讯作者：
Jing Zhang;J. Chen;Rong Chen;Guo-nan Chen;Fengfu Fu
中科院分区：
文献类型：
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作者：
Jing Zhang;J. Chen;Rong Chen;Guo-nan Chen;Fengfu Fu
本文介绍了一种新型的连接探针电化学生物传感器，用于DNA序列特异性检测，具有更高的灵敏度和更高的识别能力。这种DNA生物传感器基于“连接探针”检测策略，该策略通过称为模板增强杂交过程（TeHyP）的概念进行操作。TeHyP包含一种设计策略，即两个探针在特定温度下不会相互杂化，可以通过形成三元配合物（“Y”结结构）在模板（目标）存在的情况下相互退火。然后以[Ru(NH3)6]3+为信号分子，用电化学方法检测模板增强杂交后形成的结构。我们证明了“Y”结结构的形成通过静电相互作用将更多的[Ru(NH3)6]3+带到电极表面，并导致电化学信号增加。电化学信号的增加灵敏地反映了靶DNA的浓度，并与靶DNA的浓度呈良好的线性关系。采用上述策略，该DNA生物传感器可检测低至7.6×10−13M的目标DNA，即使对单碱基错配也具有较高的识别能力。此外，这种新型DNA生物传感器易于制造，操作方便，具有良好的稳定性、再现性和可重复使用性。
A novel junction-probe electrochemical biosensor for the sequence-specific detection of DNA with higher sensitivity and higher discrimination ability was described in here. This DNA biosensor is based on “junction-probe” detection strategy, which operates via a concept called template-enhanced hybridization processes (TeHyP). TeHyP encompasses a design strategy whereby two probes that do not hybridize to each other at a specific temperature can be made to anneal to each other in the presence of a template (target) via the formation of a ternary complex (“Y” junction structure). The resulting structure that forms after the template-enhanced hybridization then was detected by electrochemical method with [Ru(NH3)6]3+as signal molecule. We demonstrated that the formation of “Y” junction structure brings more [Ru(NH3)6]3+to the electrode surface via electrostatic interaction and results in an increasing electrochemical signal. The increasing electrochemical signal sensitively reflects the concentration of target DNA and shows a good linear relationship with the concentration of target DNA. By employing above strategy, this DNA biosensor could detect as low as 7.6×10−13M target DNA and exhibited high discrimination ability even against single-base mismatch. In addition, this novel DNA biosensor is easy to fabricate and convenient to operate, and shows good stability, reproducibility and reusability.