Co-Immobilization of Enzymes and Metals on the Covalent-Organic Framework for the Efficient Removal of Mycotoxins

Mycotoxin is an important contaminant in food and the environment. The conventional methods for detoxification of mycotoxins are plagued by high chemical consumption, secondary pollution, and specific equipment required. In this study, we propose a chemoenzymatic cascade reaction for mycotoxin removal in an effective and green manner using an enzyme-metal hybrid catalyst synthesized by compartmental co-immobilized glucose oxidase (GOx) and Fe3O4 nanoparticles (NPs) on a flower-shaped covalent organic framework (COF). The GOx-Fe3O4@COF hybrid catalyst exhibits excellent activity in mycotoxin removal due to the enrichment of mycotoxins in COF and the cooperative catalysis between GOx and Fe3O4 NPs. The degradation efficiency of aflatoxin B1 (AFB1) in the chemoenzymatic cascade reaction catalyzed by GOx-Fe3O4@COF is 3.5 times higher than that in the Fenton reaction catalyzed by Fe3O4@COF. The GOx-Fe3O4@COF hybrid catalyst is highly active in a wide pH range of 3.0-7.0, overcoming the limitation of the Fenton reaction that can only perform below pH 3.0. This study provides a powerful tool for the efficient removal of mycotoxins.