A 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 low-concentration targets, but they require several hours of reaction time, which poses a challenge for the real-time monitoring of targets within cells. Herein, a localized-CHA-based DNA tetrahedral sensor was constructed by configuring CHA hairpins onto a DNA tetrahedron. The target miRNA-10b could trigger the localized CHA reaction, which significantly improved the reaction rate compared to the free CHA reaction. The sensor exhibited a detection limit of 3.8 pM and a response time of 100 min in buffer. As a result, the sensor enables the monitoring of intracellular miRNA-10b expression levels with high sensitivity and rapid response.