Electrochemical strategy for ultrasensitive detection of microRNA based on MNAzyme-mediated rolling circle amplification on a gold electrode
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- 作者：Jianru Yang ; Min Tang ; Wei Diao ; Wenbin Cheng ; Ye Zhang ; Yurong Yan
- 关键词：Electrochemical biosensor ; Electrochemical impedance spectroscopy ; Differential pulse voltammetry ; Square wave voltammetry ; Alkaline phosphatase ; Streptavidin ; human breast adenocarcinoma ; MCF ; 7 cells ; DNA polymerase ; T4 DNA ligase
- 刊名：Microchimica Acta
- 出版年：2016
- 出版时间：November 2016
- 年：2016
- 卷：183
- 期：11
- 页码：3061-3067
- 全文大小：953 KB
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Chemistry
Analytical Chemistry
Inorganic Chemistry
Physical Chemistry
Characterization and Evaluation Materials
Monitoring, Environmental Analysis and Environmental Ecotoxicology - 出版者：Springer Wien
- ISSN：1436-5073
- 卷排序：183
文摘
The authors describe an electrochemical strategy for ultrasensitive and specific detection of microRNA (miRNA). It is based on both multicomponent nucleic acid enzyme (MNAzyme) amplification and rolling circle amplification (RCA). In the presence of target miRNAs, partial enzyme A (partzyme A) and partial enzyme B (partzyme B) are assembled to form active MNAzymes. Once formed, the MNAzymes catalyze the cleavage of the hairpin substrates to liberate biotinylated fragments which hybridized with the capture probes immobilized on a gold electrode. The RCA is then initiated to form a product that binds many detection probes. Finally, the amperometric signal (best acquired at a working voltage of 0.22 V vs. Ag/AgCl) is obtained by employing the streptavidinylated alkaline phosphatase as the enzyme. This biosensor has a 1.66 fM detection limit, and a dynamic range that extends from 10 fM to 1 nM. It displays specificity down to single mismatch discrimination of target miRNAs and good reproducibility. It was successfully applied to the determination of miRNA in total RNA samples extracted from human breast adenocarcinoma MCF-7 cells.