Localized catalytic hairpin assembly-based DNA tetrahedral sensor for sensitive and rapid miRNA detection in living cells

Abstract

Catalytic hairpin assembly (CHA) signal amplification strategies have been employed for the detection of lowconcentration targets, but it requires several hours of reaction time, which poses a challenge for real-time monitoring target within cells. Herein, a localized-CHA-based DNA tetrahedral sensor was constructed by configuring CHA hairpins onto the DNA tetrahedron. The target miRNA-10b could trigger the localized CHA reaction that significantly improved the reaction rate compared to free CHA reaction. The sensor exhibited a detection limit of 3.8 pM and response time of 100 mins in buffer. As a result, the sensor enables monitoring of intracellular miRNA-10b expression levels with high sensitivity and rapid response.