title: Multifunctional silver-embedded magnetic nanoparticles as SERS nanoprobes and their applications.
abstract: In this study, surface-enhanced Raman spectroscopy (SERS)-encoded magnetic nanoparticles (NPs) are prepared and utilized as a multifunctional tagging material for cancer-cell targeting and separation. First, silver-embedded magnetic NPs are prepared, composed of an 18-nm magnetic core and a 16-nm-thick silica shell with silver NPs formed on the surface. After simple aromatic compounds are adsorbed on the silver-embedded magnetic NPs, they are coated with silica to provide them with chemical and physical stability. The resulting silica-encapsulated magnetic NPs (M-SERS dots) produce strong SERS signals and have magnetic properties. In a model application as a tagging material, the M-SERS dots are successfully utilized for targeting breast-cancer cells (SKBR3) and floating leukemia cells (SP2/O). The targeted cancer cells can be easily separated from the untargeted cells using an external magnetic field. The separated targeted cancer cells exhibit a Raman signal originating from the M-SERS dots. This system proves to be an efficient tool for separating targeted cells. Additionally, the magnetic-field-induced hot spots, which can provide a 1000-times-stronger SERS intensity due to aggregation of the NPs, are studied.
authors.affiliation: School of Chemical and Biological Engineering, Seoul National University, Seoul 151-747, Republic of Korea.
authors.forename: Bong-Hyun
authors.initials: BH
authors.lastname: Jun
authors.forename: Mi Suk
authors.initials: MS
authors.lastname: Noh
authors.forename: Jaeyun
authors.initials: J
authors.lastname: Kim
authors.forename: Gunsung
authors.initials: G
authors.lastname: Kim
authors.forename: Homan
authors.initials: H
authors.lastname: Kang
authors.forename: Min-Soo
authors.initials: MS
authors.lastname: Kim
authors.forename: Young-Tae
authors.initials: YT
authors.lastname: Seo
authors.forename: Jongho
authors.initials: J
authors.lastname: Baek
authors.forename: Jong-Ho
authors.initials: JH
authors.lastname: Kim
authors.forename: Juyoung
authors.initials: J
authors.lastname: Park
authors.forename: Seongyong
authors.initials: S
authors.lastname: Kim
authors.forename: Yong-Kweon
authors.initials: YK
authors.lastname: Kim
authors.forename: Taeghwan
authors.initials: T
authors.lastname: Hyeon
authors.forename: Myung-Haing
authors.initials: MH
authors.lastname: Cho
authors.forename: Dae Hong
authors.initials: DH
authors.lastname: Jeong
authors.forename: Yoon-Sik
authors.initials: YS
authors.lastname: Lee
mesh_terms: D003460:Crystallization / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008280:Magnetics; D008422:Materials Testing; D008968:Molecular Conformation; D015336:Molecular Probe Techniques; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D012834:Silver