Fluorescence Enhancement Based On Silver Nanoparticles Plasmon Resonance

Fluorescent materials have unique luminescent properties and are widely used in the fields of lasers, displays, sensors, solar cells, electroluminescent devices, and biomedical research. Localized Surface Plasmon Resonance (LSPR) of silver nanoparticles (Ag NPs) offers several advantages, such as light-localization, strong absorption and local field amplification. Based on this, many applications have been developed, such as Surface Enhanced Raman Scat tering (SERS) and Metal Enhanced Fluorescence (MEF), fluorescent materials combining with Ag NPs can exhibit excellent optical properties and high photostability.In this study, Ag core-shell nanoparticles and film assembled by Ag nanoparticles were prepared. The effect of fluorescence enhancement and quenching were studied. In addition, a MEF sensor was designed for developing its application. The main works and the results are as follows:1. Tb3+/Eu3+ ions doped LaF3 phosphors have been prepared by coprecipitation method and hydrothermal method. The influences of reaction parameters on fluorescence intensity by changing doping concentration, reaction time, the kind of stabilizer and the pH value of the solution.2. The influence of Ag surface plasmon resonance on the fluorescence was investigated. Ag@SiO2@LaF3:Tb3+/Eu3+ nanoparticles and LaF3:Tb3+/PVA/Ag films on the glass were fabricated. The distance was controled by the thickness of SiO2 and the concentration of PVP between Ag NPs and LaF3:Tb3+/Eu3+ materials, respectively.3. MEF sensor (Ag@SiO2-DNA-fluorophore) was designed. The enhancement of fluorescence intensity was investigated by changing the thickness of SiO2. This sensor was used for Hg2+ detection and it exhibits high sensitivity and selectivity.