Optical properties of Ce(3+)-Nd(3+) co-doped YAG nanoparticles for visual and near-infrared biological imaging.

Ce(3+)-Nd(3+) co-doped Y3Al5O12 (YAG) nanoparticles, an average size of 20-30 nm clusters aggregated by 8-10 nm YAG nanoparticles, were synthesized by a solvothermal method. When excited by blue irradiation source, strong and broad yellow luminescence (centered at 526 nm) from Ce(3+) as well as near-infrared (NIR) luminescence (890, 1066 and 1335 nm) of Nd(3+) was observed simultaneously. It occurred by the effective dipole-dipole energy transfer from Ce(3+) to Nd(3+). Energy transfer efficiency from Ce(3+) to Nd(3+) was also calculated to be 50%. The optical property suggests that Ce(3+)-Nd(3+) co-doped YAG nanoparticles can be used as an efficient fluorescence imaging agent for not only visual but also near-infrared imaging.