Molecular Docking Insight into the Label-Free Fluorescence Aptasensor for Ochratoxin A Detection

Area of Science:

• Analytical Chemistry
• Biotechnology
• Food Safety

Background:

• Ochratoxin A (OTA) is a prevalent mycotoxin in grains, posing a global health concern.
• Accurate detection methods for OTA are crucial due to increasing contamination.
• Existing aptasensor mechanisms for OTA detection require further clarification.

Purpose of the Study:

• To develop a label-free fluorescent aptasensor for Ochratoxin A (OTA) detection.
• To elucidate the binding mechanism of the aptasensor using molecular docking.
• To evaluate the aptasensor's performance in detecting OTA in food matrices.

Main Methods:

• Construction of a G-quadruplex aptamer-based fluorescent biosensor.
• Utilizing Thioflavin T (ThT) as a fluorescent donor.
• Employing molecular docking to identify the aptamer-OTA binding site.
• Validation using spiked wheat flour samples.

Main Results:

• The aptasensor demonstrated a fluorescence decrease upon binding with OTA.
• Molecular docking identified specific binding interactions between OTA and the aptamer.
• The biosensor exhibited high selectivity, sensitivity, and excellent recovery rates in wheat flour.
• The binding mechanism involving ThT displacement was elucidated.

Conclusions:

• A novel and effective label-free fluorescent aptasensor for OTA detection was successfully developed.
• The study clarifies the binding mechanism of aptamer-based OTA detection.
• This aptasensor shows significant potential for routine monitoring of OTA in food products.