Okamoto T, Yamaguchi I, Kobayashi T
Opt Lett. 2000 Mar 15;25(6):372-4. doi: 10.1364/ol.25.000372.
A new optical sensor that uses local plasmon resonance is proposed. A peak that is due to the local plasmon resonance appears in the absorption spectrum of a gold colloid suspension in the visible region, and its height and wavelength depend on the refractive index of the suspension. These properties are used for optical sensors. We used gold colloid monolayers in which colloidal gold particles a few tens of nanometers in diameter were immobilized upon a glass slide by a functional organic coupling agent. We measured the absorption spectra of the the gold colloid monolayers, which were immersed in liquid samples or coated with thin films. We observed increases of both the resonance wavelength and the absorbance as the refractive indices of the sample liquids or the thickness of the coated films increased. The proportional constants of the resonance wavelength to the film thickness were 3.6 and 5.7 for a 13.9- and a 20.2-nm gold colloid monolayer, respectively.
提出了一种利用局域表面等离子体共振的新型光学传感器。在可见区域的金胶体悬浮液的吸收光谱中出现了一个由局域表面等离子体共振引起的峰，其高度和波长取决于悬浮液的折射率。这些特性被用于光学传感器。我们使用了金胶体单层，其中直径几十纳米的胶体金颗粒通过功能性有机偶联剂固定在载玻片上。我们测量了浸入液体样品或涂有薄膜的金胶体单层的吸收光谱。随着样品液体的折射率或涂膜厚度的增加，我们观察到共振波长和吸光度都增加了。对于13.9纳米和20.2纳米的金胶体单层，共振波长与膜厚度的比例常数分别为3.6和5.7。
