Thermodynamically controlled separation of polyvalent 2-nm gold nanoparticle-oligonucleotide conjugates

J Am Chem Soc. 2008 Apr 23;130(16):5430-1. doi: 10.1021/ja800797h. Epub 2008 Mar 28.

Abstract

We describe the synthesis of small (2-nm diameter) gold nanoparticles densely functionalized with thiolated DNA (DNA-Au NPs) and a method to separate these particles from excess free DNA after synthesis. The separation method utilizes the thermodynamically enhanced binding properties of 2-nm DNA-Au NPs, compared to free excess DNA, to selectively hybridize these small particles to larger (15-nm diameter) DNA-Au NPs and form aggregates that can be isolated by simple centrifugation. These 2-nm DNA-Au NPs are obtained in a 46% overall yield, have a high surface coverage of DNA (64.8 +/- 6.4 pmol/cm2), and as a result, exhibit increased melting temperatures and cooperative melting properties.

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 Probes / chemical synthesis*
  • Gold / chemistry*
  • Metal Nanoparticles / chemistry*
  • Nanotechnology / methods*
  • Oligonucleotides / chemistry*
  • Organometallic Compounds / chemistry*
  • Thermodynamics

Substances

  • DNA Probes
  • Oligonucleotides
  • Organometallic Compounds
  • Gold