Tailed-Hoogsteen Triplex DNA Silver Nanoclusters Emit Red Fluorescence upon Target miRNA Sensing

Area of Science:

• Biochemistry
• Molecular Biology
• Nanotechnology

Background:

• MicroRNAs (miRNAs) are key regulators of gene expression with roles in biological processes and disease.
• miRNAs are of interest as potential biomarkers for diagnosis and therapeutic strategies.
• Sensing and visualizing miRNAs are crucial for understanding their functions.

Purpose of the Study:

• To introduce a novel sensing method for target microRNAs (miRNAs).
• To utilize Tailed-Hoogsteen triplex DNA-encapsulated Silver Nanoclusters (DNA/AgNCs) for miRNA detection.
• To demonstrate the sensor's capability in vitro and in live cells.

Main Methods:

• Development of a Tailed-Hoogsteen triplex DNA/AgNCs based miRNA sensor.
• Hybridization assay for miRNA detection with a turn-on fluorescence mechanism.
• Validation using total RNA from cells and live-cell imaging.
• Mechanism elucidation via gel-fluorescence assays and small-angle X-ray scattering (SAXS).

Main Results:

• The DNA/AgNCs sensor exhibits red fluorescence upon target miRNA hybridization.
• Successful detection and visualization of miRNAs in total RNA and live cells.
• The turn-on mechanism involves a structural transition from monomer to dimer of DNA/AgNCs.
• SAXS analysis confirmed the structural transition upon miRNA sensing.

Conclusions:

• Tailed-Hoogsteen triplex DNA/AgNCs provide a sensitive and effective turn-on fluorescence sensor for miRNAs.
• The sensor is applicable for both in vitro detection and live-cell imaging of small RNAs.
• This technology shows promise for practical applications in diagnostics and biological research.