Amplification of the molecular chiroptical effect by low-loss dielectric nanoantennas.
Amplification of the molecular chiroptical effect by low-loss dielectric nanoantennas.
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DOI：
10.1039/c7nr01527e
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发表时间：
2017-05
期刊：
影响因子：
6.7
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
我们在这里报告的手旋光放大效应发生在由手性分子和硅纳米结构的混合系统。在圆偏振光的共振激发下，混合系统在光频处显示出强烈的CD感应信号，这是由Si纳米结构的电响应和磁响应引起的。更有趣的是，来自Si基介电纳米天线的诱导CD信号总是大于来自Au基等离子体对应物的诱导CD信号。相关的物理来源被披露。此外，与Au基高损耗等离子体纳米天线相比，Si基低损耗结构将产生可忽略的光热效应，这使得Si纳米天线成为以超低热损伤放大分子CD信号的最佳候选者。本研究为设计新型手性纳米传感器提供了指导，可应用于生物医学和药物学领域。
We report here the chiroptical amplification effect occurring in the hybrid systems consisting of chiral molecules and Si nanostructures. Under resonant excitation of circularly polarized light, the hybrid systems show strong CD induction signals at the optical frequency, which arise from both the electric and magnetic responses of the Si nanostructures. More interestingly, the induced CD signals from Si-based dielectric nanoantennas are always larger than that from Au-based plasmonic counterparts. The related physical origin was disclosed. Furthermore, compared to the Au-based high-loss plasmonic nanoantennas, Si-based low-loss structures would generate negligible photothermal effect, which makes Si nanoantennas an optimized candidate to amplify molecular CD signals with ultralow thermal damage. Our findings may provide a guideline for the design of novel chiral nanosensors, which are applicable in the fields of biomedicine and pharmaceutics.