Determination of microRNA-451a (miRNA-451a) by a Reduced Graphene Oxide (rGO)-Based Fluorescence Assay with Duplex-Specific Nuclease (DSN)

Abstract

MiR-451a is a biomolecule tightly related to resistance development during treatment with selective estrogen-receptor modulators for breast cancer. Accurately and sensitively monitoring its level in cells is of great significance for the drug selection and the evaluation of this cancer. However, the commonly obtainable ssDNA probe cannot efficiently enter the cell to sensitively emit reliable signals by avoiding nuclease digestion. Herein, a sensing system is reported to monitor miR-451a in living cells with high specificity and sensitivity. The system consisted of reduced graphene oxide (rGO), duplex-specific nuclease (DSN), and a fluorescence-labeled ssDNA nanoprobe. The fluorescence probe on the rGO surface provided an ultra-low background and resistance to endonuclease digestion. Duplex-specific nuclease sequentially triggered the hybridization cycle and the cleavage of ssDNA nanoprobe. The signal amplification provided a detection limit of 1 fM miR-451a using the optimal conditions with a linear range from 1 fM to 100 nM. Finally, the developed method was used to determine miR-451a in breast cancer tissue. This strategy provides a promising tool for clinical diagnosis and evaluation of miR-451a related cancer.