Target‐Mediated 5’‐Exonuclease Digestion of DNA Aptamers with RecJ to Modulate Rolling Circle Amplification for Biosensing Journal Articles uri icon

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abstract

  • AbstractWe report a new method for biosensing based on the target‐mediated resistance of DNA aptamers against 5’‐exonuclease digestion, allowing them to act as primers for rolling circle amplification (RCA). A target‐bound DNA strand containing an aptamer region on the 5’‐end and a primer region on the 3’‐end is protected from 5’‐exonuclease digestion by RecJ exonuclease in a target‐dependent manner. As the protected aptamer is at the 5’‐end, the exposed primer on the 3’‐end can participate in RCA in the presence of a circular template to generate a turn‐on sensor. Without target, RecJ digests the primer and prevents RCA from occurring, allowing quantitative fluorescence detection of both thrombin, a protein, and ochratoxin A (OTA), a small molecule, at picomolar concentrations.

publication date

  • January 5, 2022