Synthesis of surface amino-functionalized NaGdF4:Ce,Tb nanoparticles and their luminescence resonance energy transfer (LRET) with Au nanoparticles

Luminescent/magnetic dual-functional NaGdF4:Ce,Tb nanoparticles were first synthesized via a solvothermal method with rare earth stearate as the precursor, and the luminescence resonance energy transfer of NaGdF4:Ce,Tb to Au nanoparticles was studied. The synthesized NaGdF4:Ce,Tb were ellipsoidal nanoparticles, with pure hexagonal structure and an average size of 15 nm. The nanoparticles emit strong emission at 544 nm under the 246 nm excitation, and show good paramagnetic at room temperature. After surface amination by the typical Stober method, the as-prepared NaGdF4:Ce,Tb nanoparticles were served as the donor for the LRET with Au nanoparticles. Good linear relationships between the luminescence intensities of NaGdF4:Ce,Tb (at 490 nm and 544 nm) and the concentration of Au nanoparticles were obtained, indicating a great potential application prospect of the LRET system in bioassays. (C) 2011 Elsevier B.V. All rights reserved.