A dual signal amplification system with specific signal identification for rapid and sensitive detection of miRNA.

False positive which is mostly caused by the nonspecific amplification has severely hindered the development of nucleic acid detection and it is hard to avoid. Therefore, specific signals recognition and output in nucleic acid amplification are crucial to reliability of clinical diagnosis. Herein, we proposed a one-step and rapid miRNA detection strategy with specific signal identification, dual amplification and output. And this strategy was named as high-temperature hybridization chain reaction coupled with strand displacement amplification (HSA). In HSA, we well designed a target signal recognition, replication, and output probe (RRO probe). If the target miRNA exists, RRO probe can initiate a strand displacement amplification and output a target-related special single-stranded DNA (trigger). And the trigger can be identified by a high-temperature hybridization chain reaction and initiate a secondary signal amplification. As a result, the quantitative determination of HSA for miRNA-21 was in the range of 100 fM to 100 pM in 30 min, and with a detection limit of 82 fM. Moreover, with high sensitivity and rapidity, HSA has been successfully used to detect miRNA-21 in real samples.