Composites of Fe₃O₄, Ag, and Au Nanoparticles for Dye Degradation and Selective Detection of Glutathione

In comparison with the poor stability, high cost, anddifficultpreparation of conventional natural enzymes, nanozymes have the obviousadvantages of excellent stability, high catalytic activity, multifunctionality,and large-scale preparation. Herein, a series of Fe3O4 NPs-based magnetic composite with dual enzyme-like activities(peroxidase and oxidase) were successfully synthesized by the microwave-assistedmethod. Among them, the Fe3O4/Ag Au nanocompositeshowed the highest peroxidase-like activity due to the synergisticcatalytic effect of Ag and Au bimetallic modifications. Enzyme kineticstudies revealed good kinetic parameters of the Fe3O4/Ag Au nanocomposite for peroxidase, and it also exhibiteda higher affinity for TMB compared to natural horseradish peroxidase.In addition, a method for effective dye degradation and selectivedetection of glutathione was constructed based on its peroxidase-likeactivity. Importantly, the remarkable magnetic separation propertyand the outstanding stability proved the extensive application prospectsof the nanozymes in the remediation of water pollution and some biomarker-specificdetection.