title: Surface-enhanced Raman spectroscopic-encoded beads for multiplex immunoassay.
abstract: A new type of encoded bead, which uses surface-enhanced Raman scattering (SERS), is described for multiplex immunoassays. Silver nanoparticles were embedded in sulfonated polystyrene (PS) beads via a polyol method, and they were used as SERS-active substrates. Raman-label organic compounds such as 4-methylbenzenethiol (4-MT), 2-naphthalenethiol (2-NT), and benzenethiol (BT) were then adsorbed onto the silver nanoparticles in the sulfonated PS bead. Although only three kinds of encoding have been demonstrated here, various combinations of these Raman-label organic compounds have the potential to give a large number of tags. The Raman-label-incorporated particles were then coated with a silica shell using tetraethoxyorthosilicate (TEOS) for chemical stability and biocompatibility. The resulting beads showed unique and intense Raman signals for the labeled organic compounds. We demonstrated that SERS-encoded beads could be used for multiplex detection with a model using streptavidin and p53. In our system, the binding event of target molecules and the type of ligand can be simultaneously recognized by Raman spectroscopy using a single laser-line excitation (514.5 nm).
authors.affiliation: Organic Synthesis Laboratory, School of Chemical and Biological Engineering, Seoul National University, Seoul 151-747, Korea.
authors.forename: Bong-Hyun
authors.initials: BH
authors.lastname: Jun
authors.forename: Jong-Ho
authors.initials: JH
authors.lastname: Kim
authors.forename: Hyunmi
authors.initials: H
authors.lastname: Park
authors.forename: Jun-Sung
authors.initials: JS
authors.lastname: Kim
authors.forename: Kyeong-Nam
authors.initials: KN
authors.lastname: Yu
authors.forename: Sang-Myung
authors.initials: SM
authors.lastname: Lee
authors.forename: Heejeong
authors.initials: H
authors.lastname: Choi
authors.forename: Seon-Yeong
authors.initials: SY
authors.lastname: Kwak
authors.forename: Yong-Kweon
authors.initials: YK
authors.lastname: Kim
authors.forename: Dae Hong
authors.initials: DH
authors.lastname: Jeong
authors.forename: Myung-Haing
authors.initials: MH
authors.lastname: Cho
authors.forename: Yoon-Sik
authors.initials: YS
authors.lastname: Lee
mesh_terms: D007118:Immunoassay / Q000379:methods*; D013050:Spectrometry, Fluorescence; D013059:Spectrum Analysis, Raman / Q000379:methods*