Double-stranded probe modified AuNPs for sensitive and selective detection of microRNA 30a in solution and live cell

Recent advances in miRNA research have posed a new direction in biology and chemistry to uncover the complex roles of ribonucleic acids in cellular processes. A reliable sensing strategy that can monitor the miRNA expression in live cancer cells associated with bioprocesses and biomedical applications is urgently needed. Conventional miRNA sensing methods include Northern blot, microarrays and real-time quantitative PCR. However, none of them can monitor miRNA real-time expression levels in cancer cells. In this article, we reported a double-stranded DNA probe modified gold nanoparticle used as both “nano-flares” and transfection agents to quantify miR-30a in solution further visualize in live cells. This proposed strategy not only enables to quantify (in a concentration range from 5 pM to 200 pM with a detection limit of 2.4 pM) and to specifically detect miRNA levels in solution, but also allows precise and in situ monitor the changes of miRNA expression levels in live cells. The proposed method is simple and cost-effective, holding great promise for clinical applications.