CeO₂-Coated Porphyrin-Based Porous Organic Polymers as Nanozymes for Efficient Antimicrobial Activity

The efficiency of conventional medicines in treating bacterial infections has significantly decreased as a result of antibiotic resistance, which has emerged as a serious global public health concern. Many restrictions apply to the current treatments for bacterial infections, which could result in more adverse effects and problems with resistance. Therefore, it is incredibly crucial to develop nanomaterials for phototherapeutic methods that are characterized by nonresistance and high efficiency. In this work, we designed and synthesized a nanoenzyme CeO2/FePPOP composite of a porphyrin-based porous organic polymer, FePPOP, and an inorganic material, CeO2, for multimodal antimicrobial activity. By subjecting CeO2/FePPOP to a single near-infrared (NIR) light, it is possible to catalyze the production of a significant amount of reactive oxygen species (ROS). This material also has excellent light-to-heat conversion efficiency, thereby inflicting dual damage on bacteria. CeO2/FePPOP combines its excellent peroxidase-like (POD-like) activity, photodynamic (PDT), and photothermal (PTT) properties. Therefore, it demonstrates effective broad-spectrum antimicrobial activity, killing 99.9% of Gram-negative Escherichia coli and 99.6% of Gram-positive Staphylococcus aureus. This study offers innovative insights into the creation of nanomaterial antimicrobial agents amenable to phototherapeutic interventions.