CeO<sub>2</sub>‑Coated\nPorphyrin-Based Porous\nOrganic Polymers as Nanozymes for Efficient Antimicrobial Activity

The\nefficiency of conventional medicines in treating\nbacterial\ninfections has significantly decreased as a result of antibiotic resistance,\nwhich has emerged as a serious global public health concern. Many\nrestrictions apply to the current treatments for bacterial infections,\nwhich could result in more adverse effects and problems with resistance.\nTherefore, it is incredibly crucial to develop nanomaterials for phototherapeutic\nmethods that are characterized by nonresistance and high efficiency.\nIn this work, we designed and synthesized a nanoenzyme CeO<sub>2</sub>/FePPOP composite of a porphyrin-based porous organic polymer, FePPOP,\nand an inorganic material, CeO<sub>2</sub>, for multimodal antimicrobial\nactivity. By subjecting CeO<sub>2</sub>/FePPOP to a single near-infrared\n(NIR) light, it is possible to catalyze the production of a significant\namount of reactive oxygen species (ROS). This material also has excellent\nlight-to-heat conversion efficiency, thereby inflicting dual damage\non bacteria. CeO<sub>2</sub>/FePPOP combines its excellent peroxidase-like\n(POD-like) activity, photodynamic (PDT), and photothermal (PTT) properties.\nTherefore, it demonstrates effective broad-spectrum antimicrobial\nactivity, killing 99.9% of Gram-negative Escherichia\ncoli and 99.6% of Gram-positive Staphylococcus\naureus. This study offers innovative insights into\nthe creation of nanomaterial antimicrobial agents amenable to phototherapeutic\ninterventions.