DNA circuits as amplifiers for the detection of nucleic acids on a paperfluidic platform.

This article describes the use of non-enzymatic nucleic acid circuits based on strand exchange reactions to detect target sequences on a paperfluidic platform. The DNA circuits that were implemented include a non-enzymatic amplifier and transduction to a fluorescent reporter; these yield an order of magnitude improvement in detection of an input nucleic acid signal. To further improve signal amplification and detection, we integrated the enzyme-free amplifier with loop-mediated isothermal amplification (LAMP). By bridging the gap between the low concentrations of LAMP amplicons and the limits of fluorescence detection, the non-enzymatic amplifier allowed us to detect as few as 1200 input templates in a paperfluidic format.