Abstract: Objective: Herein, a novel fluorescent aptasensor based on fluorescence resonance energy transfer (FRET) was assembled with aptamer and graphene oxide (GO) for simultaneous detection of two mycotoxins. Methods: Fluorescence-labeled aflatoxin B1 (AFB1) aptamers (APT1) and fumonisin B1 (FB1) aptamers (APT2) were adsorbed on the surface of GO by π-π stacking. The fluorescence of the fluorescent groups in aptamers was quenched by GO via FRET. APT1 and ATP2 were combined with AFB1 and FB1, respectively, enabling them to be dissociated from the surface of GO and consequently restoring fluorescence. Results: The aptasensor could provide a fast and sensitive method for the detection of AFB1 and FB1. The detection limit of AFB1 was 0.15 ng/mL, and the detection line of FB1 was 0.12 ng/mL. The recoveries of AFB1 and FB1 in spiked Chinese Baijiu samples were 92.00%–100.81% and 89.00%–99.50%. Conclusion: The fluorescent aptasensor is high sensitive and specific for the simultaneous detection of the two mycotoxins, and it is also suitable for multiplex detection of other mycotoxins.

Key words: aptasensor; graphene oxide; fluorescence detection; aflatoxin B1; fumonisin B1