The preparation of core-shell magnetic silica nanospheres for enhancing magnetism and fluorescence intensity.
Recently, magnetic and luminescent composite silica with structure of micro- and nanospheres containing both magnetic (Fe3O4) nanoparticles (MPs) and quantum dots (QDs) has attracted great interests. In this study, we have prepared core-shell structure of silica spheres in which magnets are incorporated into silica core and QDs into a mesoporous silica shell by using C18-TMS (octade-cyltrimethoxysilane). MPs were synthesized by a co-precipitation method from ferrous and ferric solutions with a molecular ratio of 2:3. Monodisperse magnetic silica cores have been prepared via sol-gel reaction of TEOS (tetraethoxysilane) and water using base catalyst. The size of magnetic silica nanospheres was confirmed by dynamic laser light scattering system (DLS) and scanning electoron microscope (SEM). The pore volume and surface area were calculated by using BET after calcination. The core-shell structure plays an important role in providing more domains for MPs in silica Core and QDs in silica shell. QDs were incorporated into the mesoporous shell by hydrophobic interactions. Magnetic characterization was performed using a superconducting quantum interference device (SQUID). The optical properties of the particles were characterized with UV/Vis spectrometer, PL spectrometer, and fluorescence microscope.
Department of Chemical and Biological Engineering, Gachon University, Seongnam 461-701, Korea.
Jeong Ha
JH
Yoo
Jong Sung
JS
Kim
D003460:Crystallization / Q000379:methods*; D005453:Fluorescence; D046911:Macromolecular Substances / Q000737:chemistry; D060526:Magnetic Fields; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008422:Materials Testing; D008968:Molecular Conformation; D054118:Nanospheres / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D045663:Quantum Dots; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties
D046911:Macromolecular Substances; D058185:Magnetite Nanoparticles; D012822:Silicon Dioxide