Highly Potent Bactericidal Activity of Porous Metal‐Organic Frameworks

Abstract

Recent outbreaks of bacterial infection leading to human fatalities have been a motivational force for us to develop antibacterial agents with high potency and long‐term stability. A novel cobalt (Co) based metal‐organic framework (MOF) was tested and shown to be highly effective at inactivating model microorganisms. Gram‐negative bacteria, Escherichia coli (strains DH5alpha and XL1‐Blue) were selected to determine the antibacterial activities of the Co MOF. In this MOF, the Co serves as a central element and an octa‐topic carboxylate ligand, tetrakis [(3,5‐dicarboxyphenyl)‐oxamethyl] methane (TDM 8−) serves as a bridging linker. X‐ray crystallographic studies indicate that Co‐TDM crystallizes in tetragonal space group P$\overline 4$2 1m with a porous 3D framework. The potency of the Co‐TDM disinfectant was evaluated using a minimal bactericidal concentration (MBC) benchmark and was determined to be 10–15 ppm within a short incubation time period (<60 min). Compared with previous work using silver nanoparticles and silver‐modified TiO 2 nano‐ composites over the same time period, the MBC and effectiveness of Co‐TDM are superior. Electron microscopy images indicate that the Co‐TDM displayed distinctive grain boundaries and well‐developed reticulates. The Co active sites rapidly catalyzed the lipid peroxidation, causing rupture of the bacterial membrane followed by inactivation, with 100% recycling and high persistence (>4 weeks). This MOF‐based approach may lead to a new paradigm for MOF applications in diverse biological fields due to their inherent porous structure, tunable surface functional groups, and adjustable metal coordination environments.