title: Synthesis of highly magnetic graphite-encapsulated FeCo nanoparticles using a hydrothermal process.
abstract: The graphite encapsulation of metal alloy magnetic nanoparticles has attracted attention for biological applications because of the high magnetization of the encapsulated particles. However, most of the synthetic methods have limitations in terms of scalability and economics because of the demanding synthetic conditions and low yields. Here, we show that well controlled graphite-encapsulated FeCo core-shell nanoparticles can be synthesized by a hydrothermal method, simply by mixing Fe/Co with sucrose as a carbon source. Various Fe/Co metal ratios were used to determine the compositional dependence of the saturation magnetization and relaxivity coefficient. Transmission electron microscopy indicated that the particle sizes were 7 nm. In order to test the capability of graphite-encapsulated FeCo nanoparticles as magnetic resonance imaging (MRI) contrast agents, these nanoparticles were solubilized in water by the nonspecific physical adsorption of sodium dodecylbenzene sulfonate.
authors.affiliation: Center for Nano-Bio Fusion Research, Korea Research Institute of Chemical Technology, Daejeon, 305-600, Korea.
authors.forename: Seung Jae
authors.initials: SJ
authors.lastname: Lee
authors.forename: Jee-Hyun
authors.initials: JH
authors.lastname: Cho
authors.forename: Chulhyun
authors.initials: C
authors.lastname: Lee
authors.forename: Janggeun
authors.initials: J
authors.lastname: Cho
authors.forename: Yong-Rok
authors.initials: YR
authors.lastname: Kim
authors.forename: Joung Kyu
authors.initials: JK
authors.lastname: Park
mesh_terms: D001557:Benzenesulfonates / Q000737:chemistry; D003035:Cobalt / Q000737:chemistry*; D003102:Colloids; D003287:Contrast Media / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008279:Magnetic Resonance Imaging; D008280:Magnetics; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D013054:Spectrophotometry, Atomic; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013696:Temperature; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D001557:Benzenesulfonates; D003102:Colloids; D003287:Contrast Media; D014867:Water; D003035:Cobalt; C001114:dodecylbenzenesulfonic acid; D006108:Graphite; D007501:Iron