Studies On The Preparation And Luminescence Properties Of Rare-earth Nanomaterials Applied To Luminescent Label

With rapid development of nanoscience and nanotechnology, many nanoparticles show great academic and application values because of their unique physical and chemical properties, especially optical and biological properties. Many investigators are trying to develop various high sensitivity and selectivity detection methods and apparatuses, based on unique properties of the nanoparticles. Nanoparticles as biological fluorescence probe possess excellent optical properties, such as: a narrow, tunable, symmetric emission spectrum and a broad, continuous excitation spectrum. They are also photo-chemically stable and they have fluorescence quantum yields and long fluorescence lifetime. The high selectivity and sensitivity should be acquired when the nanoparticles are used to detect the macromolecules.This dissertation reports on the synthesis as well as the optical properties of the nanomaterials prepared by different methods with controlled phases and morphologies. They show potential application in luminescence labels. The results of this dissertation are summarized as follows:Eu³⁺-doped LaF₃ nanoparticles were prepared by a hydrothermal process at a low temperature. Well-dispersed nanoparticles with an average size of 30nm and a hexagonal shape were synthesized. In order to explore the optimal conditions to synthesis luminescent nanoparticles, we systematically investigated the influences of reaction temperature, time, initial pH and proportion of reactants on the morphology, size and luminescence of LaF₃:Eu³⁺ nanoparticles. The luminescent properties of LaF₃:Eu³⁺ nanoparticles show that fluorescent intensity of prepared samples without any further calcinations is five times stronger and Eu³⁺-doped concentration is much higher than that of bulk materials prepared by high temperature solid synthesis. Thus, the LaF₃:Eu³⁺ nanoparticles have potential application to luminescent label.Based on these results mentioned above, green-emitting LaF₃:Ce,Tb phosphor nanoparticles were synthesized by a simple hydrothermal method. Above all, the...