Activation of palindromes on a degradable modular grafting probe enables ultrasensitive detection of microRNAs.

This work describes a single-stranded degradable modular grafting probe for analyzing microRNA-21. In the system, the exonuclease activity of phi29 polymerase restrains the SYBR Green I/ssDNA induced background. The palindrome activation caused remarkable target fluorescence. The detection limit was achieved as 0.26 fM, showing potential in biochemical analysis.