Oncogenic microRNAs (miRNA), for example, miR-155, are key tumor biomarkers in cancer cells that drive tumorigenesis, and the miRNA profile signature can predict cancer development and aggressiveness. Hence, timely detection of oncogenic miRNA in living cells is highly attractive to the diagnosis of cancer at an early stage. Herein, we report a highly sequence-specific gold@polydopamine-based nanoprobe for long-term detection of miRNA in human cancer cell lines in vitro. A single administration of the nanoprobe enables continuous detection of the miR-155 expression level in living cancer cells for up to 5 days. We believe that our nanoprobe is highly promising for both oncology research and translational applications.
Keywords: cancer cellular uptake; fluorescence quenching; gold nanoprobes; long-term real-time imaging; oncogenic miRNA.