Simultaneous detection of aflatoxin B1 and ochratoxin A in food samples by dual DNA tweezers nanomachine

a dual DNA tweezers nanomachine was developed for one-step simultaneous detection of aflatoxin B1 (AFB1) and ochratoxin A (OTA) in food samples. The dual DNA tweezers are locked by the aptamers of mycotoxins, resulting the turn off of fluorescent signal. In the presence of AFB1 and OTA, the aptamers can bind with their corresponding targets, resulting the open of DNA tweezers and the turn on of the fluorescent signals. The limits of detections were 3.5 x 10(-2) ppb for AFB1 and 0.1 ppb for OTA. Moreover, the applicability of the method was further demonstrated by conducting a limited survey on 5 samples collected from various sources. The recoveries of this method change from 90.0% to 110.0% for simultaneous detection of AFB1 or OTA and the RSDs vary from 4.1% to 9.2%. Detection uncertainties were within 5% (with a 95% confidence level).

Automated summary

A dual DNA tweezers nanomachine was developed for simultaneous detection of AFB1 and OTA in food samples, achieving high sensitivity and accuracy through the binding of aptamers with their targets to control the fluorescent signals. The method demonstrated satisfactory recoveries and precision, with detection uncertainties within 5% at a 95% confidence level.