Multifunctional PNIPAM/Fe3O4-ZnS hybrid hollow spheres: synthesis, characterization, and properties.

Multifunctional PNIPAM/Fe3O4-ZnS hybrid hollow spheres integrating magnetism, luminescence, and temperature responses into one single entity have been successfully fabricated via a facile method. First, the cross-linked Poly (N-isopropylacrylamide) (PNIPAM) hollow spheres were synthesized via a classical method, named one-pot "self-removing" process. Then, Fe3O4 and ZnS nanoparticles were in situ precipitated on the surface of the PNIPAM hollow spheres. The PNIPAM/Fe3O4-ZnS hybrid hollow spheres exhibit magnetic property, which indicates the potential application in drug targeting. In addition, ZnS nanoparticles in the shell play an important role as a luminescent label for tracking the drug delivery. Meanwhile, the existence of PNIPAM provides a thermosensitive property. All these results indicate that the obtained composite can be expected to be used as a smart drug delivery material.