The real-time imaging of low-abundance
tumor-related
microRNAs (
miRNAs) in living cells holds great potential for early clinical diagnosis of
cancers. However, the relatively low detection sensitivity and possible false-positive signals of a probe in complex cellular matrices remain critical challenges for accurate
RNA detection. Herein, we developed a novel aptamer-functionalized cruciate
DNA probe that enabled amplified multiple
miRNA imaging in living cells via catalytic hairpin assembly (CHA). The cross-shaped design of the cruciate
DNA probe improved the stability against nucleases and acted as a modular scaffold for CHA circuits for efficient delivery into
tumor cells. The cruciate
DNA probe allowed self-assembly through thermal annealing and displayed excellent performance for sensitive
miRNA detection in vitro. The cruciate
DNA probe could be internalized into
nucleolin-overexpressed cells specifically via cell-targeting of the
AS1411 aptamer, achieving amplified fluorescence imaging and quantitative evaluation of the expression of
miRNAs in living cells. Through the simultaneous detection of intracellular multiple
miRNAs, the developed cruciate
DNA probe could provide more accurate information and reduce the chances of false positive signals for
cancer diagnosis. This approach offers a new opportunity for promoting the development of
miRNA-related biomedical research and
tumor diagnostic applications.