A Facile Approach to Fabrication of Bifunctional Magnetic-Optical Fe3O4@ZnS Microspheres

Bifunctional magnetic-optical Fe 3 O 4 @ZnS microspheres with core−shell heterostructures have been successfully fabricated by a simple chemical deposition method. The adsorption of sodium dodecyl sulfate (SDS) on the preformed magnetite microspheres played an essential role in directing the structure of the composites. The presented materials were characterized by FE-SEM, HRTEM, XRD, FTIR, fluorescence spectrophotometer, and SQUID MPMS. The results showed that spherical Fe 3 O 4 cores were coated by a uniform ZnS layer. The saturation magnetization value of Fe 3 O 4 @ZnS core−shell microspheres is 52.5 emu g −1 at room temperature. Ultraviolet and visible light can be easily obtained by exposing the microspheres to different excitation wavelengths. The combined magnetic and fluorescent properties endow the microspheres with great potential applications in drug targeting, bioseparation and diagnostic analysis.