Fluorescence enhancement of Tb3＋ complexes by adding silica-coated silver nanoparticles

• Published in: Science China. Chemistry Vol. 58; no. 6; pp. 979 - 985
• Main Authors: Zhou, Dan, Lin, Xuemei, Wang, Ailing, Li, Jingjing, Qu, Yanrong, Chu, Haibin, Zhao, Yongliang
• Format: Journal Article
• Language: English
• Published: Beijing Science China Press 01.06.2015; Springer Nature B.V
• Subjects: Absorption spectra; Benzoates; Benzoic acid; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Composition; Core-shell particles; Ethylenediaminetetraacetic acids; Fluorescence; Fluorine; Hydrogen bonds; Infrared analysis; Infrared spectra; Nanoparticles; Silicon dioxide; Silver; Surface plasmon resonance; Terbium; Thickness; Titration; Ultraviolet absorption; Ultraviolet spectra; 二氧化硅; 元素分析仪; 滴定法测定; 荧光增强; 表面等离子体共振; 透射电子显微镜; 银纳米颗粒; 铽配合物; halobenzoic acids; metal-enhanced fluorescence; Ag@SiO; Tb; core-shell nanoparticles; complexes
• ISSN: 1674-7291; 1869-1870
• DOI: 10.1007/s11426-014-5265-x

Six kinds of terbium ternary complexes with halo-benzoic acids were synthesized. Their compositions were determined by C, H elemental analyzer and EDTA titration. The infrared spectra, ultraviolet absorption spectra, and fluorescence spectra were also measured to identify the complexes. Elemental analysis showed that the compositions of these complexes were Tb（p-BrBA）3- H20, Tb（p-CIBA）3- 2H20, Tb（p-FBA）3- H20, Tb（o-FBA）3·2H20, Tb（o-CIBA）3· H20, and Tb（o-BrBA）3. H20, respectively. The monodispersed Ag@SiO2 core-shell nanoparticles with silica thicknesses of 10, 15, and 25 nm were success- fully prepared and characterized by transmission-electron microscopy. Fluorescence intensities of the complexes were detected before and after Ag@SiO2core-shell nanoparticles were added; the enhancement times were related to the silica-shell thick- ness. The fluorescence enhancement times were largest when the thickness of the silica shell was 25 nm. The mechanism may be attributed to the localized surface-plasmon resonance. Furthermore, the enhancement effect of terbium fluoro-benzoate complexes was the strongest in these complexes. This result may be attributed to the hydrogen bond between the hydroxyl on the surface of the silica shell and the fluorine atom.