A multi-functional nano-platform based on LiGa 4.99 O 8 :Cr 0.01 /IrO 2 with near infrared-persistent luminescence, "afterglow" photodynamic and photo-thermal functions.

Multi-functionalised nano-platforms based on persistent-luminescence nanoparticles (PLNPs) have attracted considerable attention for biomedical applications owing to their lack of background noise and suitability for in vivo imaging without the need for in situ excitation. However, nano-platforms based on PLNPs for continuous photodynamic therapy (PDT) are currently lacking. Herein, we report a nano-platform (LiGa 4.99 O 8 :Cr 0.01 /IrO 2 , LGO:Cr/IrO 2 ) prepared using PLNPs (LiGa 4.99 O 8 :Cr 0.01 , LGO:Cr) covalently bonded with iridium oxide nanoparticles (IrO 2 NPs), producing near-infrared (NIR) persistent luminescence, "afterglow" PDT and photo-thermal therapy (PTT) effects. The LGO:Cr/IrO 2 not only exhibits NIR-persistent luminescence at 719 nm and a PTT effect under 808 nm irradiation but also a continuous "afterglow" PDT effect without the need for in situ excitation owing to persistent energy transfer from LGO:Cr to the IrO 2 NPs, in turn generating reactive oxygen species (ROS). This multi-functional nano-platform is expected to further promote the application of PLNPs in tumour treatment.