摘要
采用电化学方法制备出悬浮胶体金纳米棒。在室温下测得其紫外 可见吸收光谱和荧光发射光谱。结合准静电场理论与散射理论对金纳米棒的光学特性进行了数值模拟。计算结果表明,由于金纳米棒形状的各向异性,吸收截面与散射截面均出现两个共振峰,分别对应于横截方向与长轴方向的表面等离子共振。对于几何形状一定的金纳米棒,在外围介质介电常数从1 5增加到2 5的过程中,两个共振吸收峰均增强并非线性红移。然而对于散射光谱,短波方向的共振峰线性红移,强度变化微弱;长波方向的共振峰减弱并非线性红移。
Suspended gold nanorods were synthesized via electrochemical method. UV-Visible spectra and fluorescence emission spectra were measured at room temperature. Numerical calculations based on quasi-static and scattering theories were developed to describe these observed optical properties. Because of the anisotropy of the gold nanorods, both absorption features and scattering features show two peaks, which result from the transverse and longitudinal surface plasmon resonances respectively. Furthermore, with increasing the dielectric constant of surrounding medium from 1.5 to 2.5, these two absorption peaks increase and red shift in a nonlinear way together. However, the scattering peak at the shorter wavelength depends on the surrounding medium dielectric constant in a linear fashion, and the other scattering peak at the longer wavelength decreases and red shifts nonlinearly.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2005年第6期916-919,共4页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金(60277003)
西安交通大学在职博士基金(90071201)资助项目
关键词
纳米棒
吸收
散射
荧光
介电常数
nanorods
absorption
scattering
fluorescence
dielectric constant
