PNNL

Abstract

Uniform sized colloidal nanocrystals have attracted much attention, because of their unique magnetic and optical properties, as compared with those of their bulk counterparts. Especially magnetic nanocrystals and quantum dots have been intensively pursued for biomedical applications such as contrast enhancement agents in magnetic resonance imaging, magnetic carriers for drug delivery system, biological labeling and diagnostics. Due to their large pore sizes and high surface areas, mesoporous materials and its composites with nanocrystals have attracted considerable attention. In order to use the nanocrystals as functional delivery carriers and catalytic supports, nanocrystals coated with porous silica shells are desirable. Herein, we report a synthetic procedure for the fabrication of monodisperse nanocrystals embedded in uniform pore-sized mesoporous silica spheres. As a representative example, we synthesized monodisperse magnetite (Fe3O4) nanocrystals embedded in mesoporous silica spheres and both magnetite nanocrystals and CdSe/ZnS quantum dots embedded in mesoporous silica spheres. Furthermore, these mesoporous silica spheres were applied to the uptake and controlled release of drugs.