Tri-mode fluorescence/colorimetric/strip aptasensor with CRISPR/Cas12a-driven cascade strategy for mycotoxin.

Area of Science:

• Biosensing and Nanotechnology
• Molecular Biology
• Analytical Chemistry

Background:

• Mycotoxin detection is crucial for food safety, but current methods face challenges in accessibility and efficiency.
• Multi-mode biosensors offer rapid detection, yet practical implementation remains difficult.

Purpose of the Study:

• To develop a tri-mode aptasensor for ultrasensitive quantification of ochratoxin A (OTA).
• To leverage a CRISPR/Cas12a-driven cascade strategy for enhanced detection performance.

Main Methods:

• Preparation of pre-designed probes: Apt@cDNA, fluorophore-quencher (FQ-reporter), and glucose oxidase (GOx)-reporter.
• Utilizing a CRISPR/Cas12a cascade triggered by OTA for signal amplification via CHA reaction and H2O2 generation.
• Integration of fluorescence, colorimetric, and strip detection modes.

Main Results:

• Achieved ultrasensitive detection of OTA with limits of detection (LOD) as low as 9.10 pg/mL.
• Demonstrated satisfactory specificity, accuracy, and practicability in spiked and real samples.
• Highlighted quantitative capability, homogeneous reaction, and simplified operation.

Conclusions:

• The developed tri-mode aptasensor provides a sensitive and efficient platform for OTA detection.
• CRISPR/Cas12a-driven signal amplification offers a versatile approach for harmful substance monitoring.
• This platform shows promising prospects for practical applications in food safety and related fields.