DNA box-assisted T7 transcription techniques combined with Cas13a for detection of the influenza A (H1N1) virus

The influenza A (H1N1) virus continues to undergo mutations, posing a serious threat to public health. In this study, an innovative system was developed using a transcriptional isothermal amplification scheme combined with a DNA box for detection of H1N1 RNA. The split T7 promoter was assembled on four edges of the hexahedral DNA box to form two target-capturing robotic arms. Transcribed ssRNA was accurately recognized by the Cas13a system and used the trans-cleavage activity to release a fluorescent signal. As compared to the traditional split T7 technique, the novel DNA box greatly improved the reaction rate and biological stability in complex organisms. The sensor platform strategy enabled stable and accurate detection of H1N1 RNA with detection limits as low as the fM level. In general, the proposed system provided a good sensing tool for virus diagnosis and monitoring with great potential in environmental and public health applications.