Fluorescent sensing ochratoxin A with single fluorophore-labeled aptamer

Area of Science:

• Analytical Chemistry
• Biotechnology

Background:

• Ochratoxin A (OTA) is a prevalent mycotoxin with significant health implications.
• Accurate and sensitive detection methods for OTA are crucial for food safety and quality control.

Purpose of the Study:

• To develop a novel fluorescent aptasensor for the sensitive and selective detection of ochratoxin A (OTA).
• To investigate the impact of fluorophore labeling sites on aptamer performance for OTA sensing.

Main Methods:

• Utilized a single fluorophore-labeled aptamer strategy for OTA detection.
• Screened various fluorescein labeling sites on the aptamer (internal thymine, 3'-end, 5'-end) to optimize sensing.
• Investigated the effect of labeling on aptamer affinity and OTA binding.
• Evaluated the aptasensor's performance in terms of signal-on or signal-off responses.

Main Results:

• Achieved simple, rapid, and selective sensing of OTA at nanomolar concentrations.
• Demonstrated successful detection of OTA spiked in diluted red wine, validating its use in complex matrices.
• Identified optimal labeling sites that enhanced aptamer performance for OTA detection.

Conclusions:

• The developed fluorescent aptasensor provides a promising tool for sensitive OTA detection.
• This strategy is adaptable for designing aptamer-based sensors for various other target analytes.
• The method shows potential for real-world applications in food safety monitoring.