Multifunctional CeO₂/Graphene Nanoribbon Nanozyme for Synergistic Photothermal and Chemodynamic Therapy of Tumor

Nanozymes, simulating natural enzymatic actions, have shown substantial promise in catalytic tumor therapy. Nevertheless, developing nanozymes with multiple catalytic functions for multimodal nanodiagnosis remains a challenging task. Here, we report a type of quasi-one-dimensional graphene nanoribbons (GNRs) can firmly anchor and disperse CeO 2 nanoparticles by modifying polyethylene glycol (PEG) modification to form a stable CeO 2 /GNRs-PEG nanocomposite. This material possesses multiple enzymatic activities, facilitating the transformation of H 2 O 2 into hydroxyl radicals within the tumor environment, degrading H 2 O 2 to produce O 2, and continuously converting O 2 into O 2 ·– to increase oxidative stress in the tumor microenvironment. Notably, the good photothermal effect of CeO 2 /GNRs-PEG can enhance the generation of ·OH and O 2 ·–, increasing the level of oxidative stress within cells and thereby killing tumor cells. The ability of photothermal effects to enhance the generation of oxygen from hydrogen peroxide also leads to the production of more O 2 ·– which can promote tumor ablation. Overall, multifunctional nanozymes loaded with GNRs present excellent promise as a catalytic therapy material in many fields.