A Fluorescent Aptasensor Based on Mose2 Nanosheets and Exonuclease Iii-Assisted Signal Amplification for Sensitive Detection of Zen

Abstract

Current detection methods for trace mycotoxins in the environment suffer from false negatives, false positives or low accuracy. Therefore, it is important to establish a sensitive and efficient mycotoxins detection method for food safety. In this study, a novel fluorescent aptamer sensor is proposed by interacting layered MoSe2 nanosheets (MoSe2 NSs) with a zearalenone (ZEN) aptamer-functionalised FAM probe (Apt-FAM) that specifically binds to zearalenone. The proximity of the fluorescent moiety FAM to MoSe2 NSs resulted in fluorescence quench. With the presence of ZEN, Apt-FAM can specifically bind ZEN. Using ribonucleic acid exonuclease III (Exo III) as an auxiliary signal amplification and triggering surface desorption of MoSe2 NSs, allowing fluorescence signals to be recovered. The fluorescent aptamer sensor has a good linear fluorescence response in the range of ZEN concentration from 0.05 ng/mL to 200 ng/mL.

Keywords: ZEN, fluorescent aptamer sensor, Exonuclease III, MoSe2 nanosheets