Target-triggered triple isothermal cascade amplification strategy for ultrasensitive microRNA-21 detection at...

Area of Science:

• Biochemistry
• Molecular Biology
• Analytical Chemistry

Background:

• MicroRNA-21 (miR-21) is a key biomarker for breast cancer screening and progression.
• Sensitive and selective detection methods for miR-21 are critical for clinical diagnosis.

Purpose of the Study:

• To develop a novel, highly sensitive, and selective method for quantifying miR-21.
• To achieve attomolar sensitivity for miR-21 detection using a unique amplification strategy.

Main Methods:

• A target-triggered triple isothermal cascade amplification (3TICA) strategy was employed.
• A unimolecular DNA template with recognition, amplification, and DNAzyme production units was designed.
• Amperometric detection was used to quantify the catalytic reduction of TMB.

Main Results:

• The 3TICA strategy achieved attomolar sensitivity (detection limit of 0.5 aM) for miR-21.
• The method demonstrated excellent selectivity, distinguishing single-base mismatches.
• A linear detection range from 1 aM to 100 pM was established.

Conclusions:

• The developed 3TICA strategy offers a simple, cost-effective, and highly sensitive method for miR-21 detection.
• This approach shows promise for the detection of various short oligonucleotides by modifying the template sequence.
• The strategy is valuable for breast cancer diagnostics and potentially other oligonucleotide-based assays.