A Deoxyribozyme-Initiated Self-Catalytic DNA Machine for Amplified Live-Cell Imaging of MicroRNA

Anal Chem. 2021 Aug 10;93(31):11052-11059. doi: 10.1021/acs.analchem.1c02596. Epub 2021 Jul 29.

Abstract

Functional DNA nanostructures have been widely used in various bioassay fields. Yet, the programmable assembly of functional DNA nanostructures in living cells still represents a challenging goal for guaranteeing the sensitive and specific biosensing utility. In this work, we report a self-catalytic DNA assembly (SDA) machine by using a feedback deoxyribozyme (DNAzyme)-amplified branched DNA assembly. This SDA system consists of catalytic self-assembly (CSA) and DNAzyme amplification modules for recognizing and amplifying the target analyte. The analyte initiates the CSA reaction, leading to the formation of Y-shaped DNA that carries two RNA-cleaving DNAzymes. One DNAzyme can then successively cleave the corresponding substrate and generate numerous additional inputs to activate new CSA reactions, thus realizing a self-catalytic amplification reaction. Simultaneously, the other DNAzyme is assembled as a versatile signal transducer for cleaving the fluorophore/quencher-modified substrate, leading to the generation of an amplified fluorescence readout. By incorporating a flexible auxiliary sensing module, the SDA system can be converted into a universal sensing platform for detecting cancerous biomarkers, e.g., a well-known oncogene microRNA-21 (miR-21). Moreover, the SDA system realized the precise intracellular miR-21 imaging in living cells, which is attributed to the reciprocal amplification property between CSA reactions and DNAzyme biocatalysis. This compact SDA amplifier machine provides a universal and facile toolbox for the highly efficient identification of cancerous biomarkers and thus holds great potential for early cancer diagnosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biocatalysis
  • Biosensing Techniques*
  • DNA
  • DNA, Catalytic* / metabolism
  • Fluorescent Dyes
  • MicroRNAs* / metabolism

Substances

  • DNA, Catalytic
  • Fluorescent Dyes
  • MicroRNAs
  • DNA