Synthesis and characterization of magnetic wrinkled mesoporous silica nanocomposites containing Fe3O4 or CoFe2O4 nanoparticles for potential biomedical applications

We report the preparation of magnetic wrinkled mesoporous silica (MWMS) nanocomposites by either seeding magnetic nanoparticles during the preparation of the WMS nanoparticles (Fe3O4@WMS and CoFe2O4@WMS) or by mixing via sonication of the magnetic and the wrinkled mesoporous silica (WMS) nanoparticles (WMS-Fe3O4 and WMS-CoFe2O4). The morphology and physical properties of the nanocomposites were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and dynamic light scattering. Raman spectroscopy was used to detect the magnetic nanoparticles embedded into the silica matrix or anchored on the WMS surface, as a fast and convenient analytical tool for the identification of metal oxide phases present in the magnetic nanocomposites. Depending on the preparation method, magnetic nanoparticles were located at the center of the WMS particles, producing well-defined core-shell magnetic nanocomposites or they were present anchored on the surface of the fibrous structure of the mesoporous silica nanoparticles. The resulting MWMS nanocomposites may become potentially useful in biomedical applications as drug delivery systems or contrast agents for magnetic resonance imaging.