An electrochemical biosensor for sensitive detection of microRNAs based on target-recycled non-enzymatic amplification
An electrochemical biosensor for sensitive detection of microRNAs based on target-recycled non-enzymatic amplification
复制标题
一种基于靶标回收非酶扩增灵敏检测 microRNA 的电化学生物传感器
DOI：
10.1016/j.snb.2018.05.081
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发表时间：
2018-10-15
影响因子：
8.4
通讯作者：
Gu, Yueqing
中科院分区：
文献类型：
--
作者：
Hu, Fang;Zhang, Wancun;Gu, Yueqing
本研究基于Fe（CN）（6）（3-）/Fe（CN）（6）（4-）电化学信号，利用羧基多壁碳纳米管（MWCNTs-COOH）修饰的玻碳电极（GCE）修饰DNA结构，构建了一种简单、经济、无标记的电化学生物传感器，用于高灵敏度和高选择性地检测miR-21。利用靶回收非酶扩增策略（TRNEAS）实现了生物传感器的高灵敏度和特异性，该策略依赖于序列特异性发夹链置换，并且不需要添加环境敏感的酶。此外，SP-DNA通过酰胺键与cMWCNTs/GCE严格结合，这确保了良好的电化学结果和优异的目标miRNA检测稳定性。所开发的miR-21电化学生物传感器表现出宽的线性动态范围为0.1 fmol至5 pmol和检测限为56.7阿莫尔的miR-21在体外检测。我们开发的miR-21生物传感器特别检测了miR-21的相对表达水平，并与茎环RT-PCR结果高度一致。综上所述，我们开发的电化学生物传感器在生物医学研究和早期临床诊断中具有巨大的应用潜力。
In this study, a simple, economic, and label-free electrochemical biosensor was developed for highly sensitive and selective miR-21 detection based on Fe(CN)(6)(3-)/Fe(CN)(6)(4-) electrochemical signal, which relies on DNA structures conjugating with carboxyl multi-wall carbon nanotubes (MWCNTs-COOH)-modified glassy carbon electrode (GCE). High sensitivity and specificity of the biosensor were achieved by taking advantage of the target-recycled non-enzymatic amplification strategy (TRNEAS), which relies on sequence-specific hairpin strand displacement and does not require the addition of environment-susceptible enzymes. Besides, the SP-DNA strictly binds to the cMWCNTs/GCE via amide bonds, which ensure good electrochemical results and excellent stability for target miRNA detection. The developed miR-21 electrochemical biosensor exhibited a broad linear dynamic range of 0.1 fmol to 5 pmol and a detection limit of 56.7 amol for miR-21 detection in vitro. The relative miR-21 expression levels were particularly detected by our developed miR-21 biosensor and were highly consistent with the stem-loop RT-PCR results. In summary, our developed electrochemical biosensor exhibits great potential for further application in biomedical research and early clinical diagnosis.