Effective antibacterial action of a 2D bimetallic Al/Fe-TCPP NMOF loaded with glucose oxidase by a cascade catalytic reaction and depleting glutathione simultaneously

Abstract

Nanoscale metal–organic frameworks (NMOFs) with peroxidase-mimicking activity emerged as promising antibacterial agents instead of antibiotics. Therefore, here, a novel 2D bimetallic NMOF-based antibacterial agent named Al/Fe-TCPP NMOF/GOx was constructed. Compared with the Fe-TCPP NMOF, the obtained Al/Fe-TCPP NMOF exhibited significantly improved water-solubility, which favors the production and diffusion of hydroxyl radicals (˙OH). Glucose oxidase (GOx) loaded on Al/Fe-TCPP NMOF catalyze exogenous glucose to produce gluconic acid and hydrogen peroxide (H₂O₂), which provided an acidic environment to enhance the peroxidase-like activity of Al/Fe-TCPP NMOF and provided H₂O₂ for producing ˙OH to kill bacteria. Meanwhile, Fe³⁺ in Al/Fe-TCPP NMOF/GOx can deplete GSH, which increases the concentration of ˙OH for improving the antibacterial efficiency. The result of the antibacterial experiment in vitro demonstrated that Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were nearly completely killed in the co-incubation of Al/Fe-TCPP NMOF/GOx and glucose in vitro whereas the viabilities of E. coli and S. aureus were still higher than 50% in the presence of GOx and glucose, which illustrated that the 2D bimetallic Al/Fe-TCPP NMOF/GOx + glucose possesses excellent antibacterial action on typical E. coli and S. aureus.