Size correlation of optical and spectroscopic properties for gold nanoparticles
Size correlation of optical and spectroscopic properties for gold nanoparticles
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DOI：
10.1021/jp074902z
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发表时间：
2007-10-11
影响因子：
3.7
通讯作者：
Zhong, Chuan-Jian
中科院分区：
文献类型：
--
作者：
Njoki, Peter N.;Lim, I-Im S.;Zhong, Chuan-Jian
虽然金纳米颗粒的光学和光谱性质被广泛应用于化学、生物分析和生物医学等领域，但对纳米颗粒在溶液中的尺寸与这些性质的相关性的研究还相当有限。本文描述了在水溶液中对直径从10到100 nm的金纳米颗粒进行这种关联的系统研究的结果。这些纳米颗粒的高度单分散性使得颗粒大小与表面等离子激元(SP)共振带特性和表面增强拉曼散射(SERS)光谱特性有了有意义的关联。将该关联式与基于Mie理论的模拟结果进行了比较。实验结果和理论结果之间的密切一致为确定SP共振带波长作为颗粒大小的测量方法的有效性提供了洞察力。纳米粒子在水溶液中吸附4-巯基苯甲酸的SERS强度与尺寸的相关性揭示了纳米粒子在溶液中存在一个临界尺寸，超过这个临界尺寸，颗粒间的相互作用是起作用的，并且是SERS效应的原因。这些发现为在分析或生物分析应用中利用不同尺寸的金纳米颗粒在水溶液中的光学和光谱性质提供了尺寸关联的基础。
While the optical and spectroscopic properties of gold nanoparticles are widely used for chemical, bioanalytical, and biomedical applications, the study of the size correlation with these properties for nanoparticles in solutions is rather limited. This paper describes the results of a systematic study of such a correlation for gold nanoparticles with diameters ranging from 10 to 100 nm in aqueous solutions. The high monodispersity of these nanoparticles permitted a meaningful correlation of the particle size with the surface plasmon (SP) resonance band properties and the surface-enhanced Raman scattering (SERS) spectroscopic properties. This correlation is compared to the results from the simulation based on Mie theory. The close agreement between the experimental and the theoretical results provides insight into the validity of determining the wavelength of the SP resonance band as a measure of the particle size. The size correlation with the SERS intensity from the adsorption of 4-mercaptobenzoic acid on the nanoparticles in aqueous solutions reveals the existence of a critical size of the nanoparticles in the solution beyond which the particle-particle interaction is operative and responsible for the SERS effect. These findings serve as the basis of size correlations for exploiting the optical and spectroscopic properties of gold nanoparticles of different sizes in aqueous solutions in analytical or bioanalytical applications.