Au/CeO<sub>2</sub> Nanozyme Scaffold Boosts Electron and Hydrogen Transfer for NIR-Enhanced Chemodynamic Therapy
Qi Zhong, Kangdong Wang, Pan Gao, Shuping Peng, Cijun Shuai
Abstract
CeO 2 nanozymes have demonstrated the potential to enhance biological scaffolds with chemodynamic therapy. However, their catalytic efficacy is limited by the slow conversion of Ce 4+ to Ce 3+ and the lack of substrates like H 2 O 2 and H + . To address these challenges, we adopted a dual-pronged strategy that utilized the plasmonic resonance of Au nanoparticles and their glucose-oxidase mimicry to boost electron and hydrogen transfer. Specifically, we integrated Au/CeO 2 nanozymes into poly- l -lactic acid scaffolds via selective laser sintering. This conversion of Ce 3+ to Ce 4+ in the scaffolds enhanced the reduction of H 2 O 2 to a hydroxyl radical, inducing oxidative stress in tumor cells. The Au nanoparticles played a crucial role in boosting the Ce 3+ /Ce 4+ catalytic cycle by providing both the energy and the catalytic substrates. They recycled Ce 4+ back to Ce 3+ by exploiting plasmonic-induced hot electrons and catalyzed glucose oxidation to supply H 2 O 2 and H + . Our nanoscale and atomic-scale simulations confirmed that the Au/CeO 2 hybrid structure utilized near-field coupling to amplify the plasmonic resonance and the Au–O–Ce bridge reduced the electron transfer barrier. Consequently, the Au/CeO 2 scaffold decreased the activation energy from 22.57 to 9.92 kJ/mol. These findings highlight the significant promise of the Au/CeO 2 nanozyme scaffold for NIR-enhanced chemodynamic therapy.