Self-assembled CeVO/Ag nanohybrid as photoconversion agents with enhanced solar-driven photocatalysis and NIR-responsive photothermal/photodynamic synergistic therapy performance.

The plasmonic cerium vanadate (CeVO) semiconductor and plasmonic silver (Ag) metal exhibit a localized surface plasmon resonance (LSPR) effect in the visible (Vis)-light region; however, weak absorption in the near-infrared (NIR) region restricts their environmental remediation and biomedical application. Herein, CeVO/Ag nanohybrids with self-assembled heterostructure and improved Vis/NIR light absorption were synthesized from CeVO nanosheets and AgNO solution, which could serve as potential solar-driven catalytic agents and near-infrared (NIR) light responsive anticancer agents. Oleic acid-stabilized CeVO nanosheets were modified with the HS-PEG-OH by the thiol-ene click reaction and presented self-assembly morphology in aqueous solution due to hydrophobic-hydrophobic interactions. Sulfhydryl (-SH) groups provided stable sites for Ag ions on the surface of CeVO, and Ag ions could be directly reduced by Ce ions to form CeVO/Ag heterojunction nanocrystals (NCs). Due to the higher absorption in the Vis/NIR light region than CeVO nanosheets, CeVO/Ag NCs led to the improved solar light responsive photocatalytic degradation of organic dyes. Upon the exposure of these NCs to an 808 nm laser, CeVO/Ag NCs show high photothermal conversion efficiency, ROS generation ability and photoacoustic (PA) signal for implementing PA imaging-guided photothermal/photodynamic synergistic cancer therapy with better tumor inhibition effect.