title: Size-tunable silicon/iron oxide hybrid nanoparticles with fluorescence, superparamagnetism, and biocompatibility.
abstract: Magnetic/fluorescent composite materials have become one of the most important tools in the imaging modality in vivo using magnetic resonance imaging (MRI) monitoring and fluorescence optical imaging. We report herein on a simplified procedure to synthesize hybrid nanoparticles (HNPs) that combine silicon and magnetic iron oxides consisting of magnetite (Fe(3)O(4)) and maghemite (γ-Fe(2)O(3)). Intriguingly, our unique synthetic approach can control magnetic and optical behaviors by reducing the particle size, demonstrating that the HNPs with the mean diameter of 3.0 nm exhibit superparamagnetic behavior and green fluorescence in an aqueous solution, ambient air, and a cellular environment, whereas the HNPs with the mean diameter more than 5.0 nm indicate ferromagnetic behavior without fluorescence. Additionally, both HNPs with different diameters possess excellent magnetic responsivity for external applied magnetic field and good biocompatibility due to the low cytotoxicity. Our biocompatible HNPs with the superparamagnetism can provide an attractive approach for diagnostic imaging system in vivo.
authors: Department of Physics, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy. keisuke.sato@unibo.it
authors: Keisuke
authors: K
authors: Sato
authors: Shinobu
authors: S
authors: Yokosuka
authors: Yasunori
authors: Y
authors: Takigami
authors: Kenji
authors: K
authors: Hirakuri
authors: Kouki
authors: K
authors: Fujioka
authors: Yoshinobu
authors: Y
authors: Manome
authors: Hiroaki
authors: H
authors: Sukegawa
authors: Hideo
authors: H
authors: Iwai
authors: Naoki
authors: N
authors: Fukata
mesh_terms: D045744:Cell Line, Tumor; D005290:Ferric Compounds / Q000737:chemistry* / Q000493:pharmacokinetics; D005453:Fluorescence; D006367:HeLa Cells; D006801:Humans; D008280:Magnetics; D008422:Materials Testing; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D012825:Silicon / Q000737:chemistry*
chemical_list: D005290:Ferric Compounds; C000499:ferric oxide; D012825:Silicon