Structure-switching aptasensors for sensitive detection of ochratoxin A

Area of Science:

• * Analytical Chemistry
• * Biosensing
• * Food Science

Background:

• * Ochratoxin A (OTA) is a prevalent foodborne mycotoxin posing risks to human health.
• * Sensitive and accurate detection methods for OTA are crucial for ensuring food safety.
• * Existing detection methods require improvement in sensitivity and efficiency.

Purpose of the Study:

• * To design and develop novel aptasensors for enhanced detection of Ochratoxin A.
• * To improve the sensitivity and reliability of OTA detection in food samples.
• * To create a viable tool for routine food safety inspections.

Main Methods:

• * Design of structure-switching aptamers (OTABA4 and OTABA3) based on a common OTA-binding aptamer (OTABA).
• * Construction of aptasensors utilizing split G-quadruplex and G-triplex configurations.
• * Employed thioflavin T (ThT) as a fluorescence probe, monitoring conformational changes induced by OTA binding.

Main Results:

• * Developed OTABA4-ThT and OTABA3-ThT aptasensors exhibiting significantly enhanced OTA detection sensitivity.
• * OTABA3-ThT demonstrated a 6.7-fold increase in sensitivity compared to the original aptasensor.
• * Aptasensors performed effectively in detecting OTA in real food samples (corn and peanuts).

Conclusions:

• * Structure-switching aptasensors offer a synergistic amplification mechanism for improved fluorescence signaling.
• * The developed aptasensors provide highly sensitive and reliable detection of OTA.
• * These aptasensors meet food safety inspection requirements, offering a promising tool for mycotoxin monitoring.