Star-shaped magnetite@gold nanoparticles for protein magnetic separation and SERS detection

Pedro Quaresma, Inês Osório, Gonçalo Dória, Patrícia A. Carvalho, André Pereira, Judith Langer, João Pedro Araújo, Isabel Pastoriza-Santos, Luis M. Liz-Marzán, Ricardo Franco, Pedro Baptista, Eulália Pereira

Research output: Contribution to journalArticle

63 Citations (Scopus)

Abstract

A novel synthetic methodology for star shaped gold-coated magnetic nanoparticles is reported. The coating is performed in two steps: formation of gold nuclei at the surface of magnetite nanoparticles followed by growth of the gold nuclei into a complete star shaped shell. The star-shaped gold-coated magnetic nanoparticles thus obtained preserve the magnetic properties of the precursor magnetite nanoparticles, e. g. they can be easily separated with a magnet. In addition, the gold coating provides interesting optical properties while simultaneously allowing for biofunctionalization that may be advantageous for biological applications, such as (bio)detection via surface-enhanced Raman spectroscopy (SERS). As a proof-of-concept, a capping agent terminated with a nickel(II)-nitrilotriacetate group showing high affinity for histidine was used to modify the surface of the nanoparticles. The resulting star-shaped nanoparticles were used to selectively capture histidine-tagged maltose-binding protein from a crude cell extract. Finally, the performance of star shaped gold-coated magnetic nanoparticles as SERS platforms was demonstrated through the detection of Raman active dye (Astra Blue).

Original languageEnglish
Pages (from-to)3659-3667
Number of pages9
JournalRCS Advances
Volume4
Issue number8
DOIs
Publication statusPublished - 2014

Keywords

  • IRON-OXIDE NANOPARTICLES
  • ENHANCED RAMAN-SCATTERING
  • HISTIDINE-TAGGED PROTEINS
  • BIOLOGICAL APPLICATIONS
  • BIOMEDICAL APPLICATIONS
  • SHELL NANOPARTICLES
  • SURFACE
  • NANOSTARS
  • MAGHEMITE
  • SIZE

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  • Cite this

    Quaresma, P., Osório, I., Dória, G., Carvalho, P. A., Pereira, A., Langer, J., Araújo, J. P., Pastoriza-Santos, I., Liz-Marzán, L. M., Franco, R., Baptista, P., & Pereira, E. (2014). Star-shaped magnetite@gold nanoparticles for protein magnetic separation and SERS detection. RCS Advances, 4(8), 3659-3667. https://doi.org/10.1039/c3ra46762g