Au/CeO<sub>2</sub> Nanozyme Scaffold Boosts Electron\nand Hydrogen Transfer for NIR-Enhanced Chemodynamic Therapy

CeO<sub>2</sub> nanozymes have demonstrated the potential to enhance\nbiological scaffolds with chemodynamic therapy. However, their catalytic\nefficacy is limited by the slow conversion of Ce<sup>4+</sup> to Ce<sup>3+</sup> and the lack of substrates like H<sub>2</sub>O<sub>2</sub> and H<sup>+</sup>. To address these challenges, we adopted a dual-pronged\nstrategy that utilized the plasmonic resonance of Au nanoparticles\nand their glucose-oxidase mimicry to boost electron and hydrogen transfer.\nSpecifically, we integrated Au/CeO<sub>2</sub> nanozymes into poly-l-lactic acid scaffolds via selective laser sintering. This\nconversion of Ce<sup>3+</sup> to Ce<sup>4+</sup> in the scaffolds\nenhanced the reduction of H<sub>2</sub>O<sub>2</sub> to a hydroxyl\nradical, inducing oxidative stress in tumor cells. The Au nanoparticles\nplayed a crucial role in boosting the Ce<sup>3+</sup>/Ce<sup>4+</sup> catalytic cycle by providing both the energy and the catalytic substrates.\nThey recycled Ce<sup>4+</sup> back to Ce<sup>3+</sup> by exploiting\nplasmonic-induced hot electrons and catalyzed glucose oxidation to\nsupply H<sub>2</sub>O<sub>2</sub> and H<sup>+</sup>. Our nanoscale\nand atomic-scale simulations confirmed that the Au/CeO<sub>2</sub> hybrid structure utilized near-field coupling to amplify the plasmonic\nresonance and the Au–O–Ce bridge reduced the electron\ntransfer barrier. Consequently, the Au/CeO<sub>2</sub> scaffold decreased\nthe activation energy from 22.57 to 9.92 kJ/mol. These findings highlight\nthe significant promise of the Au/CeO<sub>2</sub> nanozyme scaffold\nfor NIR-enhanced chemodynamic therapy.