Surface modification and bioconjugation of FeCo magnetic nanoparticles with proteins

Colloids Surf B Biointerfaces. 2014 May 1:117:449-56. doi: 10.1016/j.colsurfb.2013.11.050. Epub 2013 Dec 12.

Abstract

Magnetic Fe70Co30 nanoparticles with a cubic shape and a mean size of 15±1.5 nm were fabricated using a magnetron-sputtering-based gas phase condensation deposition method. The particles had a high saturation magnetization of 220 emu/g, which is much higher than that of commercially available iron oxide nanoparticles. The FeCo nanoparticles were modified by 3-aminopropyltriethoxy silane and subsequently activated by glutaraldehyde, leading to successful attachment of aldehyde groups onto nanoparticle surfaces. Three proteins, namely streptavidin, PAPP-A antibody and Nectin-4 antibody, were immobilized on glutaraldehyde activated FeCo nanoparticles, and their loading levels were quantitatively evaluated. Our results show that loading capabilities are 95 μg of streptavidin, 128 μg of PAPP-A, and 125 μg of Nectin-4 antibody per milligram of FeCo nanoparticles, and that the three immobilized proteins retain their binding bioactivity. The protein-FeCo conjugates may find valuable applications involving magnetic separation and purification of proteins and cells, and the magnetic detection of biomolecules.

Keywords: FeCo magnetic nanoparticles; Immobilization; Protein; Surface modification.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Antibodies / chemistry
  • Antibodies / metabolism*
  • Cobalt / metabolism*
  • Immunoglobulin G / chemistry
  • Iron / metabolism*
  • Magnetic Phenomena
  • Magnetite Nanoparticles / chemistry*
  • Magnetite Nanoparticles / ultrastructure
  • Microscopy, Fluorescence
  • Particle Size
  • Photoelectron Spectroscopy
  • Streptavidin / metabolism*
  • Surface Properties

Substances

  • Antibodies
  • Immunoglobulin G
  • Magnetite Nanoparticles
  • Cobalt
  • Streptavidin
  • Iron