Target Extension-Activated DNA Walker on Nanoparticles for Digital Counting-Based Analysis of MicroRNA

• 作者: Qinya Feng Yuqing Zhai Wei Ren Chenghui Liu
• 来源期刊: 中国化学（英文版）
• 年，卷（期）: 2021,（6）
• 所属期刊栏目: Concise Reports
• 页码范围: 1471-1476
• 页数: 6页
• 语种: 英文
• DOI: 10.1002/cjoc.202000692

摘要

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 abun-dance.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 accu-rately 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.