Japan Advanced Institute of Science and Technology, School of Materials Science, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan.
Philos Trans A Math Phys Eng Sci. 2010 Sep 28;368(1927):4275-92. doi: 10.1098/rsta.2010.0120.
In this paper, we demonstrate the synthesis of monodispersed silver nanoparticles (NPs) of controlled size (20.5 +/- 3.3 nm) in aqueous phase from a silver hydroxide precursor with sodium acrylate as dual reducing-capping agent. We then coat these NPs in a layer of gold with controllable thickness through a reduction-deposition process. The materials are characterized using several techniques including high-resolution transmission electron microscopy, ultraviolet-visible spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The results show that we were able to synthesize not only monodispersed Ag NPs but also core-shell Ag-Au NPs with a discrete structure, which is significant because of the challenges associated with the creation of such materials, namely the propensity of metallic Ag to be oxidized by the presence of ionic Au. The NPs are of interest for use in a wide range of potential applications, including biomedical diagnostics and biomolecular detection as well as many others.
本文展示了在水相中使用银氢氧化物前体和丙烯酸钠作为双重还原-封端试剂合成具有可控尺寸（20.5 ± 3.3nm）的单分散银纳米粒子（NPs）。然后，我们通过还原沉积过程在这些 NPs 上包覆一层可控厚度的金。通过高分辨率透射电子显微镜、紫外-可见光谱、X 射线衍射和 X 射线光电子能谱对材料进行了表征。结果表明，我们不仅能够合成单分散的 Ag NPs，还能够合成具有离散结构的核壳型 Ag-Au NPs，这是非常重要的，因为这些材料的合成存在挑战，即由于存在离子 Au，金属 Ag 容易被氧化。这些 NPs 在广泛的潜在应用中具有应用价值，包括生物医学诊断和生物分子检测以及许多其他领域。
