Fabrication of chiral plasmonic oligomers using cysteine-modified gold nanorods as monomers
Fabrication of chiral plasmonic oligomers using cysteine-modified gold nanorods as monomers
复制标题
以半胱氨酸修饰的金纳米棒为单体制备手性等离子体低聚物
DOI：
10.1007/s12274-014-0530-z
复制
发表时间：
2014-11-01
期刊：
影响因子：
9.9
通讯作者：
Wu, Xiaochun
中科院分区：
文献类型：
--
作者：
Hou, Shuai;Wen, Tao;Wu, Xiaochun
紫外光区以外的圆二色性对手性传感器和手性光学器件的研究具有重要意义。在这里，我们展示了一种简单而通用的方法，用于制造等离子体低聚物，在可见光和近红外光谱范围内具有强CD响应。通过引发半胱氨酸修饰的金纳米棒的并排组装来制造低聚物。修饰的纳米棒本身没有表现出明显的等离子体CD信号;然而，低聚物在等离子体共振波长附近显示出强的CD带。CD带的符号由吸收的半胱氨酸分子的手性决定。通过调节低聚物的尺寸、手性分子的浓度和/或纳米棒的纵横比，CD强度和光谱范围容易地可调。理论计算表明，低聚物的CD起源于低聚物内相邻纳米棒的轻微扭曲。因此，我们提出，吸附的手性分子能够操纵纳米棒之间的扭转角，从而调制的CD响应的低聚物。
Generation of circular dichroism (CD) beyond the UV region is of great interest in developing chiral sensors and chiroptical devices. Herein, we demonstrate a simple and versatile method for fabrication of plasmonic oligomers with strong CD response in the visible and near IR spectral range. The oligomers were fabricated by triggering the side-by-side assembly of cysteine-modified gold nanorods. The modified nanorods themselves did not exhibit obvious plasmonic CD signals; however, the oligomers show strong CD bands around the plasmon resonance wavelength. The sign of the CD band was dictated by the chirality of the absorbed cysteine molecules. By adjusting the size of the oligomers, the concentration of chiral molecules, and/or the aspect ratio of the nanorods, the CD intensity and spectral range were readily tunable. Theoretical calculations suggested that CD of the oligomers originated from a slight twist of adjacent nanorods within the oligomer. Therefore, we propose that the adsorbed chiral molecules are able to manipulate the twist angles between the nanorods and thus modulate the CD response of the oligomers.