Rapid detection of a dengue virus RNA sequence with single molecule sensitivity using tandem toehold-mediated displacement reactions.

A DNA tetrahedron having a single-strand DNA edge was used to detect a dengue virus RNA sequence. Novel tandem toehold-mediated displacement reactions (tTMDR) were developed to amplify the fluorescence signal from the DNA tetrahedron. Using an excess of the DNA tetrahedron each target RNA was recycled about 103 times during the tTMDR process. This amplification process was used for the sensitive detection of dengue virus RNA in this study. As few as 6 copies of RNA per sample could be detected using a photon count technique with single molecule sensitivity.