Dual Signal Enhancement by Magnetic Separation and Split Aptamer for Ultrasensitive T-2 Toxin Detection.

Area of Science:

• Food Science
• Analytical Chemistry
• Biotechnology

Background:

• T-2 toxin, a trichothecene mycotoxin from *Fusarium* species, contaminates cereals and food products, posing food safety risks.
• Existing detection methods may lack the sensitivity or efficiency required for comprehensive food safety monitoring.
• Development of rapid, sensitive, and specific detection tools for T-2 toxin is crucial.

Purpose of the Study:

• To develop an ultrasensitive biosensor for T-2 toxin detection.
• To establish a dual signal enhancement strategy using magnetic separation and split aptamers.
• To validate the biosensor's performance in real food samples.

Main Methods:

• Utilized magnetic graphene oxide (MGO) for signal enhancement and background reduction.
• Employed a split aptamer strategy with a FAM-fluorophore-labeled probe (FAM-SpA1-1) and an unlabeled probe (SpA1-2).
• Investigated the fluorescence recovery mechanism upon T-2 toxin binding and cooperative aptamer action.

Main Results:

• The MGO and split aptamer system significantly enhanced detection sensitivity.
• A linear response range of 10–500 pM and a limit of detection (LOD) of 0.83 pM were achieved.
• High recovery rates in spiked wheat (86.0–114.2%) and beer (112.0–129.6%) samples demonstrated practical applicability.

Conclusions:

• The developed biosensor offers excellent stability, reproducibility, and specificity for T-2 toxin detection.
• The dual signal enhancement strategy represents a novel approach for advancing aptamer-based mycotoxin sensors.
• This method shows significant potential for routine application in food safety surveillance.