Optical response of gold-nanoparticle-amplified surface plasmon resonance spectroscopy
Optical response of gold-nanoparticle-amplified surface plasmon resonance spectroscopy
复制标题
金纳米颗粒放大表面等离子体共振光谱的光学响应
DOI：
10.1021/jp910438q
复制
发表时间：
2010
期刊：
影响因子：
3.7
通讯作者：
K. Furuya and K. Kajikawa
中科院分区：
文献类型：
--
作者：
Y. Uchiho;M. Shimojo;K. Furuya and K. Kajikawa
提出了一种预测二维分布纳米粒子（NP）薄膜光学常数的简单形式，用于分析NP放大的表面等离子体共振。在低覆盖率（σ < 0.08）时，NP薄膜的介电常数可以用简单的表达式来计算，而在σ > 0.08时，则需要考虑NP薄膜周围极化引起的局部场。对不同条件下的局部场进行了解析计算和数值计算。通常用于计算二元介质介电常数的Clausius - Mossoti关系在NP薄膜中不成立，因为粒子间距离大和/或延迟效应。我们对不同NP覆盖率的NP膜进行了SPR测量，结果支持所提出的分析形式。最后，我们提出了一种从实验得到的NP- spr剖面中评估NP覆盖率的方法。
A simple formalism that predicts optical constants of a two-dimensionally distributed nanoparticle (NP) thin film is presented for analysis of the NP-amplified surface plasmon resonance. The dielectric constant of the NP thin film can be evaluated with simple expressions at low coverages (σ < 0.08), whereas the local fields induced by surrounding polarizations of NPs should be taken into account at coverages of σ > 0.08. Analytical and numerical calculations are carried out for evaluating the local fields at different conditions. The Clausius−Mossoti relation, which is usually used for evaluation of dielectric constants of a binary medium, does not hold in the NP thin films, because of the large interparticle distance and/or the retardation effect. We carried out SPR measurements for NP films with different NP coverages, and the results support the proposed analytical formalism. Finally we propose a procedure to evaluate the NP coverage from the NP-SPR profile experimentally obtained.