A DNAzyme Feedback Amplification Strategy for Biosensing

Meng Liu, Qiang Zhang, Dingran Chang, Jimmy Gu, John D. Brennan*, Yingfu Li

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

130 Scopus citations

Abstract

We report a signal amplification strategy termed DNAzyme feedback amplification (DFA) that takes advantage of rolling-circle amplification (RCA) and an RNA-cleaving DNAzyme (RCD). DFA employs two specially programmed DNA complexes, one composed of a primer and a circular template containing the antisense sequence of an RCD, and the other composed of the same circular template and an RNA-containing substrate for the RCD. RCA is initiated at the first complex to produce RCD elements that go on to cleave the substrate in the second complex. This cleavage event triggers the production of more input complexes for RCA. This reaction circuit continues autonomously, resulting in exponential DNA amplification. We demonstrate the versatility of this approach for biosensing through the design of DFA systems capable of detecting a microRNA sequence and a bacterium, with sensitivity improvements of 3–6 orders of magnitude over conventional methods.

Original languageEnglish (US)
Pages (from-to)6142-6146
Number of pages5
JournalAngewandte Chemie - International Edition
Volume56
Issue number22
DOIs
StatePublished - May 22 2017

Funding

Funding is provided by Natural Sciences and Engineering Research Council of Canada (NSERC), Ontario Ministry of Research and Innovation and Canada Foundation for Innovation (CFI).

Keywords

  • biosensors
  • DNAzymes
  • feedback amplification
  • RNA cleavage
  • rolling-circle amplification

ASJC Scopus subject areas

  • Catalysis
  • General Chemistry

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