Surface-Enhanced Circular Dichroism of Oriented Chiral Molecules by Plasmonic Nanostructures
Surface-Enhanced Circular Dichroism of Oriented Chiral Molecules by Plasmonic Nanostructures
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DOI：
10.1021/acs.jpcc.6b09435
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发表时间：
2017-01
影响因子：
3.7
通讯作者：
Weixuan Zhang;Tong Wu;Rong-Yao Wang;Xiangdong Zhang
中科院分区：
文献类型：
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作者：
Weixuan Zhang;Tong Wu;Rong-Yao Wang;Xiangdong Zhang
我们提出了一种严格的有限元方法来计算由纳米结构和具有电四极跃迁的定向手性分子组成的各种系统中的圆二色性（CD）。研究了被视为各向异性手性介质的取向分子材料与金属纳米结构之间的相互作用。我们的结果表明等离激元诱导的 CD 对分子的方向敏感。在许多情况下，分子电四极跃迁对总 CD 信号的贡献可以发挥关键作用。更有趣的是，我们已经证明，通过匹配纳米结构周围不同区域（被定向手性分子占据）的电磁场相位及其梯度，可以极大地改善基于四极和偶极的CD信号。不同的区域可能会产生相反符号的CD。当对仅具有所提出的纳米结构一侧的区域进行积分时，我们发现 CD 峰可能......
We present a rigorous finite element method to calculate circular dichroism (CD) in various systems consisting of nanostructures and oriented chiral molecules with electric quadrupole transitions. The interaction between oriented molecule materials, which are regarded as anisotropic chiral media, and metallic nanostructures has been investigated. Our results show that the plasmon-induced CD is sensitive to the orientations of the molecules. In many cases, the contribution of molecular electric quadrupole transitions to the total CD signal can play a key role. More interesting, we have demonstrated that both the quadrupole- and dipole-based CD signals can be improved greatly by matching the phases for the electromagnetic fields and their gradients at different regions around the nanostructures, which are occupied by the oriented chiral molecules. Different regions might produce CD of opposite sign. When integrating over regions with only one side of the proposed nanostructure, we find that the CD peak may ...