Entropy-driven reactions in living cells for assay let-7a microRNA

•An enzyme-free amplification strategy for microRNA assay is reported.•This strategy is employed to image miRNA in single cells by using entropy-driven reaction.•The method provides a high sensitivity with a detection limit of 0.27 pM of Let-7a.

Imaging of microRNA (miRNA) in living cells could facilitate the monitoring of the expression and distribution of miRNA and research on miRNA-related diseases. Given the low expression levels and even down-regulation of cellular miRNA that is associated with some diseases, enzyme-free amplification strategies are imperative for intracellular miRNA assay. In this work, we report an entropy-driven reaction for amplification assay miRNA with a detection limit of 0.27 pM. The resulting signal amplification provides excellent recognition and signal enhancement of specific miRNAs in living cells. This method supplies accurate information regarding cellular miRNA-related biological events and provides a new tool for highly sensitive and simultaneous imaging of multiple low-level biomarkers, thereby improving the accuracy of early disease diagnosis.

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