Maximizing DNA loading on a range of gold nanoparticle sizes

Anal Chem. 2006 Dec 15;78(24):8313-8. doi: 10.1021/ac0613582.


We have investigated the variables that influence DNA coverage on gold nanoparticles. The effects of salt concentration, spacer composition, nanoparticle size, and degree of sonication have been evaluated. Maximum loading was obtained by salt aging the nanoparticles to approximately 0.7 M NaCl in the presence of DNA containing a poly(ethylene glycol) spacer. In addition, DNA loading was substantially increased by sonicating the nanoparticles during the surface loading process. Last, nanoparticles up to 250 nm in diameter were found have approximately 2 orders of magnitude higher DNA loading than smaller (13-30 nm) nanoparticles, a consequence of their larger surface area. Stable large particles are attractive for a variety of biodiagnostic assays.

Publication types

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

MeSH terms

  • DNA / chemistry*
  • DNA / metabolism
  • Gold / chemistry*
  • Molecular Diagnostic Techniques*
  • Nanostructures / chemistry*
  • Particle Size
  • Polyethylene Glycols / chemistry*
  • Sodium Chloride / chemistry
  • Surface Properties


  • Polyethylene Glycols
  • Sodium Chloride
  • Gold
  • DNA