A molecular beacon biosensor for viral RNA detection based on HyCaSD strategy.

In the present study, a molecular beacon biosensor was developed to enable efficient detection of the viral RNAs using a previously described HyCaSD platform. The HyCaSD molecular beacon probes were labeled with the Cy5 and BHQ3 at each end of the hairpin probes. The fluorescent signal was detected immediately only when the molecular beacon probes specifically hybridized to the target sequence and unfolded their hairpin structures. This combination greatly improved the sensitivity with LOD of 100 copy equivalents per reaction (around 20-fold greater than the original HyCaSD). In addition, our MB-based HyCaSD demonstrated a single-step, single-tube and actual-time RNA detection procedure, thereby bringing it a major step closer to point-of-care diagnostic applications for viral infectious diseases.