Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR.
Langmuir. 2012 Jun 19;28(24):8979-84. doi: 10.1021/la2048097. Epub 2012 Feb 22.
Gold nanostars, possessing multiple sharp spikes, have emerged as promising plasmonic particles in the field of ultrasensitive sensing. We have developed a water-based method for high-yield synthesis of size-tunable anisotropic gold nanoparticles with a varying number of spiky surface protrusions, and performed systematic experimental and theoretical analyses of the optical properties of the single gold nanostars by characterizing them simultaneously with scanning electron microscopy and dark-field scattering spectroscopy. The morphologies and corresponding scattering spectra of the individual gold nanostars have been compared with electromagnetic simulations of the plasmonic resonances utilizing the finite-difference time-domain (FDTD) method. The study provides a correlation between the experimental and calculated scattering spectra and charge distributions of the different plasmon modes in the individual gold nanostars with varying numbers and relative orientations of surface protrusions. Our results provide guidelines for choosing gold nanostars with a proper number of spikes and appropriate dimensions of the core and arms for particular plasmonic applications as well as for further developing preparation methods of multispiked metal nanoparticles.
金纳米星具有多个尖锐的刺，作为超灵敏传感领域有前途的等离子体粒子而出现。我们开发了一种水相法，用于高产率合成具有不同数量的刺状表面突起的尺寸可调各向异性金纳米粒子，并通过扫描电子显微镜和暗场散射光谱同时对单金纳米星的光学性质进行了系统的实验和理论分析。利用有限差分时域 (FDTD) 方法对等离子体共振进行了电磁模拟，将单个金纳米星的形貌和相应的散射光谱与等离子体共振的电磁模拟进行了比较。该研究提供了实验和计算散射光谱之间的相关性，以及不同等离子体模式的电荷分布在具有不同数量和相对取向的表面突起的单个金纳米星中。我们的结果为选择具有适当数量的刺和适当的核心和臂尺寸的金纳米星提供了指导，以用于特定的等离子体应用，以及进一步开发多刺金属纳米粒子的制备方法。
