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Target Extension‐Activated DNA Walker on Nanoparticles for Digital Counting‐Based Analysis of MicroRNA †
Author(s) -
Feng Qinya,
Zhai Yuqing,
Ren Wei,
Liu Chenghui
Publication year - 2021
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.202000692
Subject(s) - microrna , chemistry , nanoparticle , fluorescence , dna , detection limit , fluorescence microscope , total internal reflection fluorescence microscope , microvesicles , nanotechnology , biophysics , computational biology , microbiology and biotechnology , biochemistry , chromatography , physics , gene , biology , optics , materials science , membrane
Main observation and conclusion MicroRNAs (miRNAs), especially exosomal miRNAs, are promising noninvasive biomarkers in early‐stage cancer diagnosis and disease treatment monitoring. However, their precise and sensitive quantification remains challenging due to their small size and low abundance. Herein, we have developed a nanoparticle‐confined DNA walker strategy for the specific detection of miRNA. In the existence of the target miRNA, the on‐particle DNA walking reaction will be initiated, providing a fluorescence‐positive nanoparticle. Otherwise, the nanoparticle would be fluorescence‐negative. Utilizing the total internal reflection fluorescent microscope (TIRFM) to digitally count the fluorescence‐positive nanoparticles, the proposed method possesses a detection limit of 0.2 pmol/L miRNA and can accurately distinguish the single‐base mismatched target. This design combines the merits of the DNA walker for signal amplification and the TIRFM for highly sensitive detection, paving a new way for the digital counting‐based analysis of exosomal miRNAs.