An oxidative cleavage-based HCR-CRISPR/Cas12a biosensor for highly sensitive detection of hypochlorous acid

Area of Science:

• Environmental Science
• Biotechnology
• Analytical Chemistry

Background:

• Hypochlorous acid (HClO) is a vital disinfectant but poses risks at excessive levels.
• Environmental contamination by HClO impacts human health and aquatic ecosystems.
• Sensitive detection methods for HClO are crucial for public health and environmental safety.

Purpose of the Study:

• To develop a highly sensitive and specific biosensor for detecting hypochlorous acid (HClO).
• To establish a robust platform for environmental pollutant monitoring.
• To improve water safety assessment and food quality control.

Main Methods:

• Developed an oxidative cleavage-based hybridization chain reaction (HCR)-CRISPR/Cas12a biosensor.
• Utilized a dual-lock switch mechanism involving a phosphorothioated (PS) DNA hairpin and a locked crRNA (L-crRNA).
• Leveraged HClO's cleavage activity to trigger HCR and activate Cas12a for fluorescence signal readout.

Main Results:

• The biosensor demonstrated high sensitivity and specificity for HClO detection.
• The dual-lock strategy effectively minimized nonspecific activation of the CRISPR/Cas12a system.
• Achieved reliable fluorescence signal generation through HCR-dsDNA activation of Cas12a's trans-cleavage activity.

Conclusions:

• The developed HCR-CRISPR/Cas12a biosensor provides a robust platform for sensitive HClO detection.
• This technology has significant potential for environmental pollutant monitoring, water safety, and food quality control.
• The dual-lock mechanism offers a promising strategy for enhancing biosensor performance.