Synthesis of surface enhanced Raman scattering active magnetic nanoparticles for cell labeling and sorting

Here we report the synthesis of the magnetic nanocomposite nanoparticles with Fe3O4 core and silver shell for cell imaging and separation. When the magnetic nanoparticles are decorated with surface enhanced Raman scattering (SERS) active molecules, they can be used for cell separation with unique optical signature. In this experiment, commercially available superparamagnetic nanoparticles (fluidMAG) with 50 nm diameter were used as the core. The shell layer was produced by the reduction of the silver salts. As a result of the reduction, nanocomposite magnetic nanoparticles with 60 nm diameter were obtained. To create unique SERS patterns for multiplexing, the surfaces of the nanoparticles were further modified with chloro-, bromo-, or fluorobenzenethiol. When these nanoparticles were incubated with 3T3 cells, it was found that the nanoparticles were located around the nucleus in the cytoplasm.

[1]  R. Dasari,et al.  Surface-enhanced Raman scattering and biophysics , 2001 .

[2]  C. Lieber,et al.  Nanowire Nanosensors for Highly Sensitive and Selective Detection of Biological and Chemical Species , 2001, Science.

[3]  R N Zare,et al.  Probing individual molecules with confocal fluorescence microscopy. , 1994, Science.

[4]  Sun,et al.  Monodisperse FePt nanoparticles and ferromagnetic FePt nanocrystal superlattices , 2000, Science.

[5]  S. Majetich,et al.  Magnetization directions of individual nanoparticles , 1999, Science.

[6]  Wenru Zhao,et al.  Fabrication of uniform magnetic nanocomposite spheres with a magnetic core/mesoporous silica shell structure. , 2005, Journal of the American Chemical Society.

[7]  Joseph Irudayaraj,et al.  Surface-enhanced Raman scattering based nonfluorescent probe for multiplex DNA detection. , 2007, Analytical chemistry.

[8]  Dwight G Nishimura,et al.  FeCo/graphitic-shell nanocrystals as advanced magnetic-resonance-imaging and near-infrared agents , 2006, Nature materials.

[9]  Catherine C. Berry,et al.  Functionalisation of magnetic nanoparticles for applications in biomedicine , 2003 .

[10]  J. Storhoff,et al.  Selective colorimetric detection of polynucleotides based on the distance-dependent optical properties of gold nanoparticles. , 1997, Science.

[11]  Jinwoo Cheon,et al.  Artificially engineered magnetic nanoparticles for ultra-sensitive molecular imaging , 2007, Nature Medicine.

[12]  Sang Bok Lee,et al.  Magnetic nanotubes for magnetic-field-assisted bioseparation, biointeraction, and drug delivery. , 2005, Journal of the American Chemical Society.