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CRISPR/HCR-powered ratiometric fluorescence aptasensor for ochratoxin A detection
Xiaokun Wang1, Hao Ding1, Yinghui Sun1
1Shandong Provincial Key Laboratory of Biochemical Engineering, College of Biological Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
Food Chemistry
|December 19, 2024
Summary
A new ratiometric fluorescent aptasensor detects ochratoxin A (OTA) in food. This CRISPR/Cas12a-based method offers highly sensitive and reliable trace analysis, crucial for food safety.
Area of Science:
- Biosensing
- Molecular Diagnostics
- Food Safety
Background:
- Ochratoxin A (OTA) is a prevalent food contaminant requiring sensitive detection methods.
- Existing detection techniques may lack the sensitivity or reliability needed for trace analysis in complex food matrices.
Purpose of the Study:
- To develop a highly sensitive and reliable ratiometric fluorescent aptasensor for trace ochratoxin A (OTA) detection in food.
- To integrate CRISPR/Cas12a, hybridization chain reaction (HCR), and horseradish peroxidase (HRP)-induced inner filter effect (IFE) for enhanced detection.
Main Methods:
- A ratiometric fluorescent aptasensor was designed utilizing CRISPR/Cas12a for specific OTA recognition.
- The system employs HCR and an HRP-induced inner filter effect (IFE) for signal amplification.
- OTA triggers CRISPR/Cas12a, which inhibits HCR, modulating HRP activity and leading to a ratiometric fluorescence output.
Main Results:
- The aptasensor achieved a "signal-on" detection mechanism with a wide linear range from 0.1 pM to 10 nM.
- A low detection limit of 0.0417 pM for OTA was established.
- The method demonstrated excellent reproducibility (RSDs < 3.87%) and high recovery rates (90.1%-110.6%) in real food samples.
Conclusions:
- The developed CRISPR/Cas12a-based aptasensor provides a sensitive and reliable platform for trace OTA detection in food.
- This innovative approach holds significant potential for improving food safety monitoring and diagnostics.

