title: Synthesis and characteristic of the Fe3O4@SiO2@Eu(DBM)3.2H2O/SiO2 luminomagnetic microspheres with core-shell structure.
abstract: The core-shell structured luminomagnetic microsphere composed of a Fe(3)O(4) magnetic core and a continuous SiO(2) nanoshell doped with Eu(DBM)(3).2H(2)O fluorescent molecules was fabricated by a modified Stöber method combined with a layer-by-layer assembly technique. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), confocal microscopy, photoluminescence (PL), and superconducting quantum interface device (SQUID) were employed to characterize the Fe(3)O(4)@SiO(2)@Eu(DBM)(3).2H(2)O/SiO(2) microspheres. The experimental results show that the microshpere has a typical diameter of ca. 500 nm consisting of the magnetic core with about 340 nm in diameter and silica shell doped with europium complex with an average thickness of about 80 nm. It possesses magnetism with a saturation magnetization of 25.84 emu/g and negligible coercivity and remanence at room temperature and exhibits strong red emission peak originating from electric-dipole transition (5)D(0)-->(7)F(2) (611 nm) of Eu(3+) ions. The luminomagnetic microspheres can be uptaken by HeLa cells and there is no adverse cell reaction. These results suggest that the luminomagnetic microspheres with magnetic resonance response and fluorescence probe property may be useful in biomedical imaging and diagnostic applications.
authors.affiliation: State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Lu
authors.forename: Ji-Lin
authors.initials: JL
authors.lastname: Zhang
authors.forename: Yan-Lin
authors.initials: YL
authors.lastname: Liu
authors.forename: De-Hui
authors.initials: DH
authors.lastname: Sun
authors.forename: Gui-Xia
authors.initials: GX
authors.lastname: Liu
authors.forename: Guang-Yan
authors.initials: GY
authors.lastname: Hong
authors.forename: Jia-Zuan
authors.initials: JZ
authors.lastname: Ni
mesh_terms: D052203:Ferrosoferric Oxide / Q000138:chemical synthesis / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D049449:Luminescence; D008280:Magnetics; D046529:Microscopy, Electron, Transmission; D008863:Microspheres; D057054:Molecular Imaging; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D012822:Silicon Dioxide / Q000138:chemical synthesis / Q000737:chemistry*; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: C504558:Eu(III)-dibenzoylmethanate; D009942:Organometallic Compounds; D014867:Water; D012822:Silicon Dioxide; D052203:Ferrosoferric Oxide