Mackiewicz Marilyn R, Ayres Benjamin R, Reed Scott M
Department of Chemistry, Portland State University, Portland, OR 97207, USA.
Nanotechnology. 2008 Mar 19;19(11):115607. doi: 10.1088/0957-4484/19/11/115607. Epub 2008 Feb 18.
Phosphatidylcholine (PC) is a versatile ligand for synthesizing gold nanoparticles that are soluble in either organic or aqueous media. Here we report a novel route to organic-soluble, PC-stabilized gold nanoparticles that can be re-suspended in water after removal of the organic solvent. Similarly, we show that PC-stabilized gold nanoparticles synthesized in water can be re-suspended in organic solvents after complete removal of water. Without complete removal of the solvent, the nanoparticles retain their original solubility and do not phase transfer. This change in solvent preference from organic to aqueous and vice versa without the use of an additional phase transfer reagent is novel, visually striking, and of utility for synthetic modification of nanoparticles. This approach allows chemical reactions to be performed on nanoparticles in organic solvents followed by conversion of the products to water-soluble materials. A narrow distribution of PC-stabilized gold nanoparticles was obtained after phase transfer to water as characterized by UV-visible (UV-vis) spectroscopy and transmission electron microscopy (TEM), demonstrating that the narrow distribution obtained from the organic synthesis is retained after transfer to water. This method produces water-soluble nanoparticles with a narrower dispersity than is possible with direct aqueous synthesis.
磷脂酰胆碱（PC）是一种用于合成可溶于有机或水性介质的金纳米颗粒的通用配体。在此，我们报告了一种制备有机可溶性、PC稳定的金纳米颗粒的新途径，该纳米颗粒在去除有机溶剂后可重新悬浮于水中。同样，我们表明在水中合成的PC稳定的金纳米颗粒在完全去除水后可重新悬浮于有机溶剂中。若不完全去除溶剂，纳米颗粒将保持其原始溶解性且不会发生相转移。在不使用额外相转移试剂的情况下，溶剂偏好从有机转变为水性，反之亦然，这种变化是新颖的、视觉上引人注目的，且对纳米颗粒的合成修饰具有实用性。这种方法允许在有机溶剂中对纳米颗粒进行化学反应，随后将产物转化为水溶性材料。通过紫外可见（UV-vis）光谱和透射电子显微镜（TEM）表征，相转移至水后获得了窄分布的PC稳定的金纳米颗粒，这表明从有机合成中获得的窄分布在转移至水后得以保留。该方法产生的水溶性纳米颗粒的分散度比直接水相合成的更窄。
