Graphene Oxide Synergy with the Conjugation of DNA and Quantum Dots for the Sensitive Detection of Ochratoxin A

Ochratoxin A (OTA) is one of the most common toxins in food and feed, which seriously affects the health of public. Herein, a convenient biosensor for OTA detecting was built based on graphene oxide (GO) and quantum dots-aptamer (QDs-aptamer) in this investigation. The results in our study demonstrated that the constructed biosensor shows excellent sensitivity and highly selectivity for OTA. A lower limit of detection of 376.3 pM (equivalent to 0.152 ng·mL−1) was achieved in the linear range from 0.5 to 20 nM (R2 = 0.996) under optimized conditions. In addition, the constructed sensor was challenged by testing coffee and red wine samples that contained buffer solution spiked with different concentrations of OTA. Considering easy operating and superior sensitivity, it has great potential, provides a high-performance platform for OTA testing in complicated food sample, and also affords a pathway for analysis of other aptamer-specific molecules.