کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1163004 | 1490916 | 2016 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Cascaded strand displacement for non-enzymatic target recycling amplification and label-free electronic detection of microRNA from tumor cells Cascaded strand displacement for non-enzymatic target recycling amplification and label-free electronic detection of microRNA from tumor cells](/preview/png/1163004.png)
• Amplified and sensitive detection of microRNA from tumor cells is achieved.
• Signal amplification is realized by two cascaded strand displacement reactions.
• The developed sensor is selective and label-free without involving any enzymes.
The monitoring of microRNA (miRNA) expression levels is of great importance in cancer diagnosis. In the present work, based on two cascaded toehold-mediated strand displacement reactions (TSDRs), we have developed a label- and enzyme-free target recycling signal amplification approach for sensitive electronic detection of miRNA-21 from human breast cancer cells. The junction probes containing the locked G-quadruplex forming sequences are self-assembled on the senor surface. The presence of the target miRNA-21 initiates the first TSDR and results in the disassembly of the junction probes and the release of the active G-quadruplex forming sequences. Subsequently, the DNA fuel strand triggers the second TSDR and leads to cyclic reuse of the target miRNA-21. The cascaded TSDRs thus generate many active G-quadruplex forming sequences on the sensor surface, which associate with hemin to produce significantly amplified current response for sensitive detection of miRNA-21 at 1.15 fM. The sensor is also selective and can be employed to monitor miRNA-21 from human breast cancer cells.
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Journal: Analytica Chimica Acta - Volume 916, 15 April 2016, Pages 1–7