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Synthesis and Biomedical Applications of Uniform-sized Oxide Nanocrystals

Taeghwan Hyeon 

Seoul National Unversity, School of Chemical and Biological Engineering (SNU), Seoul 151-744, Korea, South


We developed new generalized synthetic procedures to produce monodisperse nanocrystals of many transition metals and their oxides without a size selection process. The synthesized nanocrystals include g-Fe2O3, Fe3O4, CoFe2O4, MnFe2O4, NiO, and MnO. We report the ultra-large-scale (10s of grams) synthesis of monodisperse nanocrystals of magnetite, MnO, CoO, MnFe2O4, CoFe2O4, cube-shaped iron, ZnO, CeO2 by the thermolysis of metal-oleate complexes. We synthesized uniform-sized nanocrystals of various oxides via non-hydrolytic sol-gel reactions. We synthesized spherical zirconia nanocrystals with high-temperature tetragonal crystal phase, uniform ZnO nanocrystals with cone, hexagonal cone, and rod shapes, and anatase TiO2 nanorods with uniform diameter of 3.4 nm, CeO2 nanowires as thin as 1.2 nm, Sm2O3 nanobeams with uniform thickness of 1.4 nm using non-hydrolytic sol-gel reactions. We developed various kinds of nanostructured materials for biomedical applications. We reported on the fabrication of monodisperse nanoparticles embedded in uniform pore-sized mesoporous silica spheres. The magnetic separation (guiding) was demonstrated, and they were also investigated as drug delivery carriers. We developed a simple, reproducible, and general method of preparing multifunctional nanoparticle assembled silica spheres. Magnetite nanoparticles along with other kinds of nanoparticles were simultaneously assembled on uniform silica spheres. We fabricated magnetic gold nanoshells consisting of gold nanoshells (for NIR photothermal therapy) that are embedded with Fe3O4 nanoparticles (for MRI contrasting agent), and conjugated them with cancer targeting agent (for targeting). We synthesized Ni/NiO core/shell nanoparticles and applied them to the selective binding and subsequent magnetic separation of histidine-tagged proteins. We developed a new nanoparticle-based T1 MRI contrast agent for in vivo molecular and cellular imaging.


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Presentation: Invited at E-MRS Fall Meeting 2007, Symposium A, by Taeghwan Hyeon
See On-line Journal of E-MRS Fall Meeting 2007

Submitted: 2007-03-11 14:31
Revised:   2009-06-07 00:44