Atomic-Scale Full-Size Engineering of Platinum Nanozymes Enables High-Efficiency Catalytic Therapy

Metal particle size has a significant influence on the activity of nanozymes, yet size-dependent nanozymatic catalysis under the same metal loadings in full scale (from single atom, cluster to nanoparticle) is a challenging task and has been rarely reported. Herein, porous SiO₂ nanoflower surface-confined Pt-based nanozymes with the same metal loadings but different particle sizes were rationally designed and synthesized for antibacterial and cascade catalytic tumor therapy. The particle size-activity relationship is well established, presenting a volcanic curve, and the Pt_NC/SiO₂ nanocluster (NC) nanozyme exhibits optimized peroxidase-like activity and bactericidal efficacy compared with SAzyme and nanozyme. Furthermore, a synergistic therapeutic platform (Lap@Pt_NC/SiO₂) is constructed through the adsorption of the prodrug β-lapachone (Lap), achieving high-efficiency cascade enzymatic catalysis for tumor therapy thereby. The cluster nanozymes not only present optimized activity during the full-size engineering but also demonstrate great potential in next-generation antibacterial and tumor catalytic therapy.