Dougan Jennifer A, Karlsson Camilla, Smith W Ewen, Graham Duncan
Centre for Molecular Nanometrology, WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral St., Glasgow, Scotland, G1 1XL, UK.
Nucleic Acids Res. 2007;35(11):3668-75. doi: 10.1093/nar/gkm237. Epub 2007 May 8.
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.
用寡核苷酸功能化的金金属纳米颗粒通常采用末端硫醇修饰，并已用于广泛的应用中。尽管很容易获得，但以这种方式制备的寡核苷酸-纳米颗粒缀合物在暴露于各种小分子或高温时缺乏稳定性。如果用银代替金，那么这种稳定性的缺乏会更加明显。在本研究中，我们报告了使用简单的寡核苷酸修饰合成高度稳定的寡核苷酸-纳米颗粒缀合物。使用经修饰的固体支持物，通过用硫辛酸的N-羟基琥珀酰亚胺酯处理来生成3'-硫辛酸修饰的寡核苷酸。不同寻常的是，本研究中对金和银纳米颗粒都进行了研究，结果表明，与单硫醇类似物相比，这些二硫键修饰的寡核苷酸探针在用二硫苏糖醇（DTT）处理时，纳米颗粒的稳定性有显著提高。这是寡核苷酸-纳米颗粒缀合物稳定性方面的一项重大进展，首次使得制备出比标准金-硫醇功能化纳米颗粒更稳定的银纳米颗粒成为可能。这为使用用寡核苷酸功能化的银纳米颗粒作为金的替代品开辟了可能性。
