Fabrication of highly fluorescent multiple Fe3O4 nanoparticles core-silica shell nanoparticles

The synthesis of hybrid nanoparticles with multiple functions from the economical and scalable perspective is an important issue in nanoparticle engineering. Herein, we report a representative example of multi-functional nanosystems simultaneously possessing fluorescence and magnetism as well as the excellent structural properties of nanosilica. Highly fluorescent multiple Fe3O4 nanoparticles core-silica shell nanoparticles (FL multi-Fe3O4@SiO2 NPs) are successfully synthesized and fully characterized. The multiple Fe3O4 nanoparticles can be uniformly and collectively encapsulated within a silica matrix using a reverse microemulsion (RM) method. Fluorescent dyes are successfully functionalized through the sequential hydrolysis and condensation of tetraethylorthosilicate (TEOS) and 3-(aminopropyl) triethoxysilane (APTES). Both organic (fluorescein) and inorganic (Rubpy) dyes can be used to generate the FL multi-Fe3O4@SiO2 NPs. These synthetic paradigms for multi-functional nanoparticles can significantly facilitate the fabrications of unique nanomaterials widely applied in a variety of areas.