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...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.展开更多
基金the National Natural Science Foundation of China(Nos.22074088 and 21904083)the Program for Changjiang Scholars and Innovative Research Team in University(IRT_15R43)the Fundamental Research Funds for the Central Universities(Nos.GK202003038,GK201901003,2020TS089,GK202101001).
文摘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.
