Self‐Assembly of Bidirectional‐Signal Nanoclusters for Two miRNAs Simultaneously Monitoring in Single Cancer Cells

Abstract

A novel finding is herein reported that the bidirectional‐signal nanoclusters self‐assemble simultaneously on the nanoflowers as a result of four‐way folding (FWF) nanoprobes and DNA rolling circle replication reactions. The functionalized FWF nanoprobe containing the identification region for two targets monitoring and the trigger region for amplification signals is first used to activate the clustered amplification for two cancer‐related microRNAs (miRNAs) assays in single cells. Furthermore, the self‐assembled nanoclusters with two‐way amplification signals can provide more reliable information in situ in individual cell. Importantly, this new method can significantly distinguish cancer cells from normal cells and identify changes in the expression levels of cancer‐related miRNAs for single cells. These findings have exciting potential to provide new opportunities for detection and enhance the accuracy of early disease diagnosis.

Ratiometric Fluorescence Imaging of Intracellular MicroRNA with NIR-Assisted Signal Amplification by a Ru-SiO2@Polydopamine Nanoplatform

“…Accurate and sensitive fluorescence imaging of intracellular microRNA (miRNA) is essential for understanding its fundamental role in life evolution and pathological process, which is of great importance for the prevention and diagnosis of disease. , However, due to the low abundance of miRNA − and the complexity of cell microenvironment − that is full of various kinds of nucleases, proteins, and small biomolecules, the intracellular fluorescence detection of miRNA is still a great challenge. Recently, some nanomaterial-based ratiometric sensing platforms have shown great application prospects for the sensitive and accurate in vivo fluorescence detection of miRNA. , On the one hand, the unique photonic, electronic, and magnetic properties endow these nanomaterials with multiple possibilities to integrate with capture DNA probes for the effective output of ratiometric signals. − In comparison with single-intensity-based fluorescent probes, the ratiometric probes taking advantage of the ratio of two fluorescence signals for the quantitative assay are more accurate since their self-calibration feature can decrease errors from probe internalization efficiency, light excitation and scattering, and cell microenvironment. − On the other hand, the nanomaterial-based probes are more sensitive and stable since their large surface areas are beneficial for the assembly of a large amount of capture or fuel DNA probes and their steric hindrance can well protect the assembled probes from nucleases digestions. − …”