Label-free fluorescence turn-on detection of microRNA based on duplex-specific nuclease and a perylene probe

• A novel label free and fluorescence turn on method for the detection of microRNA.
• A duplex-specific nuclease (DSN) was used for signal amplification.
• Controlled aggregation/disaggregation of a perylene probe was used for assay signal transduction.
• The proposed assay method is simple, convenient, cost effective, sensitive and selective.

A novel fluorescence turn-on microRNA (miRNA) detection method based on duplex-specific nuclease (DSN) and a perylene probe is presented in this study. A positively charged perylene derivative (compound 1) was used as the fluorescent probe. Compound 1 exhibits strong monomer fluorescence in an aqueous buffer solution. It is well known that single-stranded DNA is a polyanion in nature. Thus, it can induce the aggregation of compound 1 through strong electrostatic, hydrophobic and π−π stacking interactions. As a result, the fluorescence of compound 1 was efficiently quenched. When the target miRNA was added, the formation of DNA-RNA hybridized duplex initiated the cleavage of the DNA strand by DSN cycle reaction, which resulted in disaggregation of compound 1. A fluorescence turn-on signal was detected, and a novel miRNA sensing method was therefore established. The presented method is label-free, simple, cost effective, sensitive and selective.

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