Tetrahedral DNA framework based CRISPR electrochemical biosensor for amplification-free miRNA detection

Area of Science:

• Biomolecular Engineering
• Nanotechnology
• Analytical Chemistry

Background:

• MicroRNAs (miRNAs) are key cancer biomarkers, but their low-level detection is challenging for point-of-care (POC) diagnostics.
• Existing clustered regularly interspaced short palindromic repeats (CRISPR)/Cas13a RNA detection methods are often complex and unsuitable for POC applications.

Purpose of the Study:

• To develop a simple, amplification-free, and sensitive CRISPR-based electrochemical biosensor for miRNA detection.
• To enable portable and rapid point-of-care diagnostics for cancer biomarkers.

Main Methods:

• Construction of a three-dimensional tetrahedral DNA framework integrated with CRISPR/Cas13a and an electrochemical biosensor (CRISPR-E).
• All-on-chip integration of activation, Cas13a cleavage, and signal readout.
• Detection of miRNA-19b using the developed CRISPR-E biosensor.

Main Results:

• Achieved a linear detection range of 10 pM to 10^4 pM for miRNA-19b with a detection limit of 10 pM.
• Demonstrated excellent selectivity, distinguishing miRNA-19b from miRNA-197.
• Validated consistent results in both buffer and mimic serum samples.

Conclusions:

• The developed CRISPR-E biosensor provides a highly sensitive and selective platform for miRNA detection.
• The all-on-chip, amplification-free strategy is well-suited for portable point-of-care diagnostic applications.
• This technology holds promise for early cancer diagnosis and monitoring.