Tuning the luminescence properties of samarium and dysprosium complexes by Ag@SiO2 nanoparticles

Two kinds of spherical core-shell Ag@SiO2 nanoparticles with the shell thicknesses of 26 and 41 nm have been prepared by a modified-Stöber method. Their size, morphology and structure are characterized by transmission electron microscopy (TEM) and scanning electron microscope (SEM). Eight kinds of samarium and dysprosium complexes with benzoic acid (BA), o-aminobenzoic acid (OABA), m-aminobenzoic acid (MABA) and p-aminobenzoic acid (PABA) are synthesized and subsequently bound to the surface of Ag@SiO2 nanoparticles. The luminescence intensities of these complexes are enhanced by the core-shell Ag@SiO2 nanoparticles. And the enhancement times not only depend on the shell thickness of the Ag@SiO2 nanoparticles, but also varies with the amino positions of aminobenzoic acid. The luminescence intensities of Dy complexes with MABA are enhanced as high as 2.3 times by the Ag@SiO2 nanoparticles with the shell thicknesses of 41 nm.