Enhanced oligonucleotide-nanoparticle conjugate stability using thioctic acid modified oligonucleotides

Jennifer A. Dougan, Camilla Karlsson, W. Ewen Smith, Duncan Graham

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113 Citations (Scopus)

Abstract

Metallic nanoparticles of gold functionalized with oligonucleotides conventionally use a terminal thiol modification and have been used in a wide range of applications. Although readily available, the oligonucleotide–nanoparticle conjugates prepared in this way suffer from a lack of stability when exposed to a variety of small molecules or elevated temperatures. If silver is used in place of gold then this lack of stability is even more pronounced. In this study we report the synthesis of highly stabilized oligonucleotide–nanoparticle conjugates using a simple oligonucleotide modification. A modified solid support was used to generate 3′-thioctic acid modified oligonucleotides by treatment with an N-hydroxysuccimidyl ester of thioctic acid. Unusually, both gold and silver nanoparticles have been investigated in this study and show that these disulphide-modified oligonucleotide probes offer significant improvements in nanoparticle stability when treated with dithiothreitol (DTT) compared with monothiol analogues. This is a significant advance in oligonucleotide–nanoparticle conjugate stability and for the first time allows silver nanoparticles to be prepared that are more stable than standard gold-thiol functionalized nanoparticles. This opens up the possibility of using silver nanoparticles functionalized with oligonucleotides as an alternative to gold.
Original languageEnglish
Pages (from-to)3668-3675
Number of pages8
JournalNucleic Acids Research
Volume35
Issue number11
Early online date8 May 2007
DOIs
Publication statusPublished - 2007

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Keywords

  • nanoparticles
  • gold
  • oligonucleotides
  • silver

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