Aptamer-Based Fluorometric Ochratoxin A Assay Based on Photoinduced Electron Transfer

Area of Science:

• Analytical Chemistry
• Biochemistry
• Molecular Biology

Background:

• Ochratoxin A (OTA) is a harmful mycotoxin found in food.
• Accurate and sensitive detection methods for OTA are crucial for food safety.
• Existing detection methods may involve complex procedures or hazardous chemicals.

Purpose of the Study:

• To develop a novel, quencher-free fluorescent detection method for ochratoxin A (OTA).
• To utilize photoinduced electron transfer (PIET) between guanine and a fluorophore for OTA detection.
• To establish a sensitive, specific, and reliable assay for OTA in real-world samples.

Main Methods:

• A carboxyfluorescein (FAM)-labeled aptamer was designed to interact with OTA.
• The method relies on the fluorescence quenching/recovery mechanism based on PIET.
• Optimal conditions were determined for the assay, and its performance was evaluated.

Main Results:

• The assay demonstrated a low detection limit of 1.3 nM for OTA under optimal conditions.
• The method exhibited high sensitivity and specificity for OTA detection.
• The assay's reliability was confirmed through successful application in detecting OTA in red wine samples.

Conclusions:

• A novel, facile, and quencher-free fluorescent method for OTA detection was successfully developed.
• The method leverages PIET and aptamer-OTA specific binding for sensitive and reliable detection.
• This approach holds potential for detecting other toxins by modifying the aptamer component.