title: Magnetically controllable dual-mode nanoprobes for cell imaging with an onion-liked structure.
abstract: A magnetically controllable dual-mode optical probe is demonstrated for cellular imaging with an onion-liked structure, which can exhibit both surface enhanced Raman scattering (SERS) and fluorescence signals. For obtaining such a nanoprobe, Fe3O4 nanoparticles were first encapsulated into an inner layer of silica, which were then coated with a second layer of gold nanoshell (designated as Fe3O4@SiO2@Au). By adjusting the thickness of the gold shell, the surface plasmon resonance (SPR) of Fe3O4@SiO2@Au nanoparticles can be easily tuned from visible to near-infrared (NIR) region. Afterwards, the prepared Fe3O4@SiO2@Au nanoparticles were tagged with a third layer of Raman reporters to exhibit SERS signals and further coated with an outmost layer of dye-doped silica to generate fluorescence. When being excited at different wavelengths as 515nm and 633nm, the distinct fluorescence and SERS signals can be separately observed. More interestingly, an enhanced cellular uptake of the presented nanoprobes was observed in the presence of a magnetic field, which was proved by both fluorescence and SERS images. This onion-liked multi-modal nanoplatform has great potential in bio-imaging, targeted delivery applications and biological separations.
authors.affiliation: Advanced Photonics Center, Southeast University, Nanjing 210096, Jiangsu, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.forename: Zhuyuan
authors.initials: Z
authors.lastname: Wang
authors.forename: Xueqin
authors.initials: X
authors.lastname: Ma
authors.forename: Shenfei
authors.initials: S
authors.lastname: Zong
authors.forename: Yiping
authors.initials: Y
authors.lastname: Cui
mesh_terms: D052203:Ferrosoferric Oxide / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D060526:Magnetic Fields; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D057054:Molecular Imaging / Q000295:instrumentation / Q000379:methods*; D012235:Rhodamines / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D020349:Surface Plasmon Resonance; D013499:Surface Properties
chemical_list: D005456:Fluorescent Dyes; D058185:Magnetite Nanoparticles; D012235:Rhodamines; D006046:Gold; D012822:Silicon Dioxide; C027755:rhodamine isothiocyanate; D052203:Ferrosoferric Oxide
keywords: Cell imaging; Fluorescence; Magnetic; Multi-mode; Onion-liked structure; Surface enhanced Raman scattering