Protein separation and identification using magnetic beads encoded with surface-enhanced Raman spectroscopy

Anal Biochem. 2009 Aug 1;391(1):24-30. doi: 10.1016/j.ab.2009.05.005. Epub 2009 May 9.

Abstract

This article presents a prototype of a surface-enhanced Raman spectroscopy (SERS)-encoded magnetic bead of 8mum diameter. The core part of the bead is composed of a magnetic nanoparticle (NP)-embedded sulfonated polystyrene bead. The outer part of the bead is embedded with Ag NPs on which labeling molecules generating specific SERS bands are adsorbed. A silica shell is fabricated for further bioconjugation and protection of SERS signaling. Benzenethiol, 4-mercaptotoluene, 2-naphthalenethiol, and 4-aminothiophenol are used as labeling molecules. The magnetic SERS beads are used as substrates for protein sensing and screening with easy handling. As a model application, streptavidin-bound magnetic SERS beads are used to illustrate selective separation in a flow cytometry system, and the screened beads are spectrally recognized by Raman spectroscopy. The proposed magnetic SERS beads are likely to be used as a versatile solid support for protein sensing and screening in multiple assay technology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aniline Compounds / chemistry
  • Biotin / chemistry
  • Magnetics*
  • Metal Nanoparticles / chemistry
  • Naphthalenes / chemistry
  • Phenols / chemistry
  • Polystyrenes / chemistry
  • Proteins / analysis*
  • Proteins / isolation & purification
  • Silver / chemistry
  • Spectrum Analysis, Raman / methods*
  • Streptavidin / chemistry
  • Streptavidin / isolation & purification
  • Sulfhydryl Compounds / chemistry
  • Surface Properties

Substances

  • Aniline Compounds
  • Naphthalenes
  • Phenols
  • Polystyrenes
  • Proteins
  • Sulfhydryl Compounds
  • Silver
  • Biotin
  • thiophenol
  • 4-aminothiophenol
  • Streptavidin
  • 2-naphthalenethiol