CRISPR/Cas12a dual-mode biosensor for Staphylococcus aureus detection via enzyme-free isothermal amplification

Area of Science:

• Biotechnology
• Biosensor Technology
• Molecular Diagnostics

Background:

• Accurate detection of Staphylococcus aureus (S. aureus) is critical for healthcare and food safety.
• Existing detection methods may lack the required sensitivity or speed for certain applications.

Purpose of the Study:

• To develop a novel dual-mode biosensor for sensitive and reliable detection of S. aureus.
• To integrate CRISPR/Cas12a with enzyme-free isothermal amplification for enhanced detection.

Main Methods:

• Utilized CRISPR/Cas12a system with hybridization chain reaction (HCR) and catalytic hairpin assembly (CHA) for signal amplification.
• Employed dual-mode detection leveraging CRISPR/Cas12a's cis-cleavage for fluorescence and trans-cleavage for electrochemical signals.
• Developed an aptamer-triggered response for S. aureus detection.

Main Results:

• Achieved a low limit of detection (LOD) of 5.7 CFU mL⁻¹ (electrochemical) and 133.7 CFU mL⁻¹ (fluorescence).
• Demonstrated high accuracy, stability, and sensitivity in detecting S. aureus.
• Successfully validated the biosensor's performance in analyzing actual samples.

Conclusions:

• The developed dual-mode biosensor provides a powerful and sensitive tool for rapid S. aureus identification.
• This approach shows significant potential for next-generation biosensors in clinical and food safety applications.
• Future work will focus on simplifying the detection process for resource-limited settings.