Synthesis and Luminescence Properties of Dy,Cr Co-doped ZnGa2O4 Persistent Luminescence Nanoparticles

Dy3+, Cr3+ co-doped ZnGa2O4 persistent luminescence nanoparticles (PLNPs) with long near-infrared afterglow were synthesized by an ethylene glycol assisted hydrothermal method. Persistent luminescence properties of the PLNPs are improved and size of the PLNPs is controlled efficiently via optimization of reaction condition, modification of zinc ratio and co-doping of Dy3+ ion. The results show that the PLNPs have long afterglow time more than 72 h and small grain size of approximately 6 nm, when the pH of the reaction solution, Ga:Zn ratio and doping amount of Dy3+ are 7, 2: 1.2 and 1%, respectively. The as-prepared PLNPs exhibit great potential as a molecular probe for biomedical imaging with high signal to noise ratio.