Immobilized CeO2@C-N Heterogenous Structures with Enhanced Dual Modal Photodynamic/Photothermal Bacterial Inactivation Under NIR Laser Irradiation

Non-antibiotic fungicides are urgently needed due to the potential threat of drug-resistant bacteria to human health. In this research, a novel antibacterial nanoplatform based on CeO 2 @C-N has been developed to achieve rapid near-infrared (NIR) laser-induced sterilization. The prepared CeO 2 @C-N hybrid material exhibited a nanowire-like structure, with dispersed CeO 2 nanoparticles averaging 5 nm in size within the heterogeneous configuration. X-ray photoelectron spectroscopy (XPS) and Raman spectra revealed that the heterogenous structures have a significant amount of oxygen vacancies and defects. Notably, CeO 2 @C-N has a narrower band gap than CeO 2 , which allows for broader absorbance extending to the NIR region. With these unique physiochemical properties, CeO 2 @C-N could inactivate E. coli and MRSA at a low concentration (20 mg/L) under 808 nm NIR laser (1 W/cm 2 ) irradiation. The excellent bactericidal activity of CeO 2 @C-N is attributed to the combination of photodynamic and photothermal processes, based on its excellent photo-thermal conversion property, detection of reactive oxygen species (ROS) ( 1 O 2 and ⋅OH) under light irradiation, and scavenger quenching experiment results. This study offers a feasible and efficient way to fabricate a highly effective antibacterial candidate.