A versatile Y shaped DNA nanostructure has been developed for simple, rapid and one-step simultaneous detection aflatoxin B1 (AFB1) and ochratoxin A (OTA). Y shaped duplex DNA arms was formed with two DNA tweezer at the ends. The aptamer sequence at the third end can bind to its target mycotoxins with strong affinity and then release the two DNA fragments. The released DNA fragments can open the DNA tweezers at the ends of Y shaped DNA arm. The amounts of AFB1 and OTA can be quantitative detection through the recovery of the fluorescent intensities. This strategy is simple and rapid with self-powered DNA hybridization reaction to control the "open" of Y shaped DNA tweezers. Furthermore, it can be finished in 60 min with only one-step of operation. The linear range of AFB1 was from 0.5 to 200 ng/mL (R2 = 0.995) and linear relationship of OTA was obtained from 4 to 300 ng/mL (R2 = 0.990). It also has been successfully applied for mycotoxins detection in real food samples. Importantly, the target mycotoxins can be extended to others by simply replacing the corresponding aptamer sequences.
Keywords: Aflatoxin B1; Aptamer; DNA nanostructure; Mycotoxin; Ochratoxin A.
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