An ultrasensitive aptasensor based on fluorescent resonant energy transfer and exonuclease-assisted target recycling...

Patulin (PAT) is a type of mycotoxin which can compromise both food quality and human health. Due to its harmful effects, strict monitoring of PAT contents in food systems is necessary. A novel kind of bioassay was proposed for determining PAT based on the fluorescent resonant energy transfer (FRET) strategy. The exonuclease-catalyzed target recycling strategy was employed to improve the sensitivity of the FRET system. The results showed that the linear range extends from 0.01 ng/mL to 100 ng/mL. Furthermore, the average recoveries ranged from 93.33% to 105.21%, confirming the reliability of this method. The total analysis time for our assay developed is about 50 min. Compared to traditional analytical methods, the developed assay is more stable and has a significantly lower detection of limit (0.003 ng/mL). We believe the approach developed in this study would be useful for high-throughput screening of PAT in food industry and government laboratory.