SPR and SERS characteristics of gold nanoaggregates with different morphologies
SPR and SERS characteristics of gold nanoaggregates with different morphologies
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DOI：
10.1007/s00340-008-3193-1
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发表时间：
2008-10-01
影响因子：
2.1
通讯作者：
Ozaki, Y.
中科院分区：
文献类型：
--
作者：
Hossain, M. K.;Kitahama, Y.;Ozaki, Y.
在这项研究中，表面等离子体共振（SPR）和表面增强的拉曼散射（Sers）特性的金纳米聚集体具有不同的形貌进行检查，阐明SPR和SERS的对象之间的相关性。通过将胶体金纳米颗粒固定在玻璃基底上来制备纳米聚集体，其被定义为随机聚集体（以下称为RA）、细长聚集体（以下称为EA）和二维层状聚集体（以下称为2DLA）。在RA和EA样品中观察到的颜色变化指示在样品上激发的局部SPR激发的变化。RA样品除了在较长波长区域（类似于700 nm）中的另一个峰之外，主要显示出以570 nm为中心的加宽和移位的SPR峰，而在EA样品中，除了以570 nm为中心的加宽峰之外，还观察到在450 nm附近的弱蓝移峰，该加宽峰覆盖了700 nm附近的另一个峰的踪迹。在2DLA样品的情况下，在较长波长区域中观察到多于一个SPR峰。Sers观察证实了使用被染料分子吸附的金纳米聚集体至少在拉曼强度上的百万倍增强。与RA和2DLA样品相比，金纳米颗粒的EA样品在拉曼信号中显示出类似于5倍的增强。
In this study, surface plasmon resonance (SPR) and surface-enhanced Raman scattering (SERS) characteristics of gold nanoaggregates with different morphologies are examined to elucidate the correlation between SPR and SERS of the object. Nanoaggregates, defined as random aggregates (hereafter RA), elongated aggregates (hereafter EA) and two-dimensional layered aggregates (hereafter 2DLA) are fabricated by immobilizing colloidal gold nanoparticles on glass substrates. The color variation observed in the RA and EA samples indicates the variation in localized SPR excitations excited on the samples. The RA sample mostly shows a broadened and shifted SPR peak centered at 570 nm in addition to another peak in the longer wavelength region (similar to 700 nm), whereas in the EA sample a weak blue-shifted peak is observed near 450 nm in addition to a broadened peak centered at 570 nm covering a trail for another one near 700 nm. In the case of the 2DLA sample, more than one SPR peaks are observed in the longer wavelength region. The SERS observation confirms million times higher enhancement at least in Raman intensity using the gold nanoaggregates adsorbed by dye molecules. The EA sample of gold nanoparticles shows similar to 5 times higher enhancement in Raman signal compared to that of the RA and 2DLA sample.