Ultrasmall Hollow Gold-Silver Nanoshells with Extinctions Strongly Red-Shifted to the Near-Infrared
Ultrasmall Hollow Gold-Silver Nanoshells with Extinctions Strongly Red-Shifted to the Near-Infrared
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DOI：
10.1021/am2008322
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发表时间：
2011-09-01
影响因子：
9.5
通讯作者：
Lee, T. Randall
中科院分区：
文献类型：
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作者：
Vongsayat, Varadee;Vittur, Brandon M.;Lee, T. Randall
制备了尺寸在40~100 nm之间的中空金-银纳米壳层。这些粒子由一个中空的球形银壳组成，周围环绕着一层薄薄的金层。通过改变加入到小银核模板悬浮液中的金汤溶液的体积，我们定制了中空的金银纳米壳层，使其具有从可见光到近红外光谱区域的强可调光学消光，消光通常集中在类似950 nm的位置。用动态光散射(DLS)、场发射扫描电子显微镜(FE-SEM)和透射电子显微镜(TEM)对这些核壳纳米粒子的尺寸和形貌进行了表征。分别用X射线衍射仪(XRD)、能谱仪(EDS)和X射线光电子能谱(XPS)测定了它们的元素组成，并用UV-Vis光谱对它们的光学性能进行了评价。由于与在近红外波长强吸收的其他纳米颗粒相比，它们的尺寸相对较小，因此这些易于合成的颗粒应可用于需要消光舒适地超过可见光波长的超小纳米颗粒的应用(例如，药物疗法、诊断成像、纳米流体和显示技术)。
Hollow gold-silver nanoshells having systematically varying sizes between 40 and 100 nm were prepared. These particles consist of a hollow spherical silver shell surrounded by a thin gold layer. By varying the volume of the gold stock solution added to suspensions of small silver-core templates, we tailored the hollow gold-silver nanoshells to possess strong tunable optical extinctions that range from the visible to the near-IR spectral regions, with extinctions routinely centered at similar to 950 nm. The size and morphology of these core/shell nanoparticles were characterized by dynamic light scattering (DLS), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). Separately, X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) were used for measuring their elemental composition; UV-vis spectroscopy was used to evaluate their optical properties. Given their relatively small size compared to other nanoparticles that absorb strongly at near IR wavelengths, these easy-to-synthesize particles should find use in applications that require ultrasmall nanoparticles with extinctions comfortably beyond visible wavelengths (e.g., medicinal therapies, diagnostic imaging, nanofluidics, and display technologies).