纳米Ag@SiO_2核壳结构的表面等离子体共振效应对铕配合物的荧光增强作用(英文)

分别制备了二氧化硅壳层厚度为10、25和80 nm的三种Ag@S O2纳米粒子,合成了铕与不同比例苯甲酸根(BA)的配合物、铕与1,10-邻菲罗啉(phen)及2,2′-联吡啶(bpy)的配合物,并对其进行表征.表征结果推测配合物的组成为Eu(BA)nCl3-n·2H2O(n=1,2,3)、Eu(phen)Cl3·2H2O和Eu(bpy)Cl3·2H2O.配合物的荧光光谱显示,在加入Ag@Si O2纳米粒子后,复合物的荧光强度有不同程度的增加,这可能是由于表面等离子体共振造成的.不同硅壳厚度的Ag@Si O2纳米粒子的荧光增强顺序是25 nm80 nm10 nm,这表明二氧化硅核壳厚度约25 nm时有较强的表面等离子体共振效应.此外,在这些复合物中,Eu(phen)Cl3·2H2O复合物的增强效果是最强的,而Eu(BA)nCl3-n·2H2O的增强效果是最弱的.在三个苯甲酸铕配合物中,Eu(BA)3·2H2O的增强效果最弱,其他两个苯甲酸铕复合物增强效果相对较好.原因可能是含氮配合物(Eu(phen)Cl3·2H2O和Eu(bpy)Cl3·2H2O)可以和Ag@SiO2更好地成键,而苯甲酸铕配合物和Ag@Si O2纳米粒子的作用相对较弱.Ag@SiO2纳米粒子有望应用于增强稀土材料的发光.

Surface Plasmon Resonance Enhanced Luminescence of Europium Complexes with Ag@SiO2 Core-Shell Structure

Three types of Ag@SiO₂ nanoparticles with silica shell thicknesses of around 10, 25, and 80 nm were prepared. Europium complexes with benzoate (BA) in different proportions, 1, 10-phenanthroline (phen) and 2, 2'-bipyridine (bpy), were synthesized and characterized. The results suggest that the complexes have the formulas Eu(BA)_nCl_3-n ·2H₂O (n=1, 2, 3), Eu(phen)Cl₃ ·2H₂O, and Eu(bpy)Cl₃ ·2H₂O. The luminescence spectra of the complexes showed that adding Ag@SiO₂ nanoparticles increased the fluorescence intensity. The fluorescence enhancement sequence of the different silica shell thickness Ag@SiO₂ nanoparticles was 25 nm> 80 nm>10 nm, which showed that the local surface plasmon resonance was strongest at the silica shell thickness of about 25 nm. Furthermore, the enhancement effect for the Eu(phen)Cl₃·2H₂O complex was the strongest and that for the benzoic complex Eu(BA)_nCl_3-n·2H₂O was the weakest in these complexes. For the three benzoic complexes, the enhancement effect of Eu(BA)₃·2H₂O was the lowest. The nitrogenous complexes (Eu(phen)Cl₃ and Eu(bpy)Cl₃) could combine withAg@SiO₂ nanoparticles very well, while the interaction of Eu(BA)₃· 2H₂O with Ag@SiO₂ nanoparticles was weaker. Ag@SiO₂ nanoparticles are expected to enhance luminescence of rare earth materials.