Highly biocompatible sub-50-nm monodisperse superparamagnetic Fe3O4@SiO2 core/shell nanoparticles with luminescent silica shells were synthesized by a w/o-microemulsion technique. And then these nanoparticles were coated with the covalently bonded biocompatible polymer poly(ethylene glycol) (PEG) and modified with the biological cancer targeting ligand folic acid (FA). After characterized by means of powder X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier transformed infrared spectroscopy (FT-IR), Thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), UV-vis, fluorescence spectroscopy and confocal laser scanning microscopy (CLSM), we confirmed that Fe3O4@SiO2 (FITC)-PEG-FA nanocomposites (SMNPs-FA) could be efficiently taken up by HeLa cancer cells and KB cells which are of over-expression of folate receptors. The multifunctional nanomaterials exhibited superparamagnetic, monodisperse, highly biocompatible, intensively fluorescent and capable of recognizing and binding cells that overexpress folate receptors, which would be useful for targeting cell imaging and provide an excellent platform for further development of an efficient cancer therapy.

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2005)Degradation of dye wastewater containing reactive brilliant blue X-BR using a rotating electrochemical disc process, Progress in Natural Science, 15:S1, 149-153To link to this article: http://dx.

In this study, the size-uniform (5-6 nm), nearly spherical, and well-dispersed aqueous Fe3o4 magnetic nanoparticles were prepared by an improved chemical coprecipitation method. The DDAT-terminated (S-1-Dodecyl-S'-(alpha,alpha'-dimethyl-alpha"-acetic acid) trithiocarbonate) polymethacrylic (PMA-DDAT) was chosen as the apt surfactant, and the terminal DDAT can be used as a high efficient RAFT chain-transfer agent for further functionalization. Then, the functionalized Fe3O4 reacted with 4-amino-2,2,6,6-tetramethyl-piperidine-oxyl (4-NH2-TEMPO) to give the spin labeling magnetic nanoparticles. Finally, the multifunctional MNPs was characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), electron paramagnetic resonance (EPR), Fourier transform infrared spectrometer (FT-IR), and vibrating-sample magnetometer (VSM). The obtained highly water-soluble, superparamagnetic, and multifunctional magnetic nanoparticles should find potential applications in biomedical research.

The effects of the addition of three different organosiloxanes, 3-aminopropyltrimethoxysilane (APTMS), 3-aminopropyltriethoxysilane (APTES) and 3-mercaptopropyltrimethoxysilane (MPTMS), on the phase behavior and the pore size of the surfactant-extracted materials have been investigated using powder XRD, TEM, Nitrogen adsorption/desorption isotherms and elemental analysis. The organosiloxanes were added to a typical synthesis, which results in a KIT-6 type in the absence of organosiloxanes. Their addition resulted in mesophase transformation or not, depending on the nature of functional groups of organosiloxanes. Increasing the content of APTMS or APTES in the silica sources not only led to the transformation of mesostructures from cubic bicontinuous Ia-3d to mixed mesostructure then towards two-dimensional (2-D) hexagonal p6mm and eventually to disordered structure, but also caused an increase of the pore size. However, the d spacing and the pore size of the cubic bicontinuous Ia-3d mesoporous solids can be decreased by addition of MPTMS between 0 and 2.5 mol% in the silica sources without a distinct decrease in the long-range order of the material. These results are discussed in terms of differences in the ability of the organosiloxanes to interact with the surfactant P123. The potential applications of these mesoporous materials are supports for the immobilization of enzymes, heavy metal sorbents, base catalysts, etc.