Highly Emissive Dye-Sensitized Upconversion Nanostructure for Dual-Photosensitizer Photodynamic Therapy and Bioimaging.

Rare-earth-based upconversion nanotechnology has recently shown great promise for photodynamic therapy (PDT). However, the NIR-induced PDT is greatly restricted by overheating issues on normal bodies and low yields of reactive oxygen species (ROS, O). Here, IR-808-sensitized upconversion nanoparticles (NaGdF:Yb,Er@NaGdF:Nd,Yb) were combined with mesoporous silica, which has Ce6 (red-light-excited photosensitizer) and MC540 (green-light-excited photosensitizer) loaded inside through covalent bond and electrostatic interaction, respectively.