Enzyme assisted magnetic hybrids as self-activated cascade reagent with synergistic activity for antimicrobial application

The abuse of antibiotics seriously threatens the public health, which leads to the urgent need to develop novel antimicrobial strategies. Reactive oxygen species (ROS) have been considered as an alternative approach for bacterial inactivation. At present, magnetic materials, especially iron oxide (Fe3O4) nanoparticles have gained widely application in biomedical field. Owing to the intrinsic peroxidase-like activity, Fe3O4 can catalyze the decomposition of hydrogen peroxide (H2O2) to generate hydroxyl radical (⋅OH) under acidic conditions. Recently, Fe3O4-based peroxidase mimics have been developed for wound infection therapy. However, the direct introduction of H2O2 with relative high concentration may induce undesired effect to normal tissues, and the infection site with near neutral pH still limits the antibacterial efficiency. Herein, carboxyl modified Fe3O4 immobilized silver nanoparticles (Ag NPs) and glucose oxidase (GOx) were synthesized as a self-activated cascade regent. GOx endowed the hybrids with catalytic activity, which could convert glucose into gluconic acid, which activated the peroxidase-like activity of Fe3O4 by decreasing the pH value. Moreover, the self-supplied H2O2 was subsequently catalyzed by Fe3O4 to generate ⋅OH. By combining the excellent antimicrobial performance of Ag NPs, the enzyme assisted magnetic hybrids exhibited robust antibacterial activity, which exhibited a great potential in bacteria-infected wound therapy.