A Triple-Signal Output Lateral Flow Platform Leveraging CRISPR/Cas12a and Nanozyme Cascades for Ultra-Sensitive...

Area of Science:

• Food Science
• Biosensor Technology
• Analytical Chemistry

Background:

• Aflatoxin B1 (AFB1) is a potent carcinogen found in agricultural products, posing significant food safety risks.
• Existing aptasensor methods for AFB1 detection face limitations in sensitivity due to inefficient strand displacement.

Purpose of the Study:

• To develop a highly sensitive and specific multireadout lateral flow assay for the detection of AFB1.
• To overcome the sensitivity limitations of current aptasensors through integrated signal amplification strategies.

Main Methods:

• Developed a "three-in-one" assay integrating CRISPR/Cas12a activity with PtPdRu nanozyme-mediated amplification.
• Utilized a "locked activator" DNA configuration for AFB1-specific activation of CRISPR/Cas12a.
• Employed fluorescence and colorimetric readouts with a smartphone app for signal amplification and detection.

Main Results:

• Achieved ultrasensitive AFB1 detection with a limit of detection of 0.22 pg/mL.
• Demonstrated a 13-fold and 2.7-fold improvement in sensitivity compared to fluorescence and intrinsic colorimetric modes, respectively.
• Showcased high specificity in detecting AFB1 in spiked corn and peanut samples.

Conclusions:

• The developed multireadout aptasensor offers a sensitive and versatile platform for AFB1 detection in agricultural products.
• The integration of CRISPR/Cas12a and nanozyme amplification significantly enhances detection sensitivity and specificity.
• This approach provides a valuable tool for ensuring food safety and protecting public health from mycotoxin contamination.