Proximity rolling circle amplification based generation of lighting-up aptamer for sensitive and label-free MicroRNA...

Area of Science:

• Biochemistry
• Molecular Biology
• Analytical Chemistry

Background:

• MicroRNA (miRNA) dysregulation is linked to pneumonia.
• Ultrasensitive detection of miRNAs is challenging due to their low abundance and short sequences.

Purpose of the Study:

• To develop a label-free, highly sensitive detection method for miRNA-21.
• To overcome the technical challenges in miRNA quantification for clinical applications.

Main Methods:

• A catalytic hairpin assembly-triggered proximity rolling circle transcription system was designed.
• The system synthesizes malachite green (MG)-binding RNA aptamers for signal generation.
• Target miRNA-21 initiates hairpin probe rearrangement, activating dual rolling circle transcription.

Main Results:

• Ultrasensitive detection of miRNA-21 down to 0.51 fM was achieved.
• The assay demonstrated high specificity, distinguishing miRNA-21 from mismatched sequences.
• A robust fluorescence signal was generated upon MG dye binding to aptamers.

Conclusions:

• The developed assay offers a sensitive and specific platform for miRNA-21 detection.
• This method shows potential for monitoring miRNA-21 in clinical samples.
• The strategy is adaptable for detecting other trace biomarkers.