Amplification of the molecular chiroptical effect by low-loss dielectric nanoantennas

作者：Zhang, Weixuan; Wu, Tong; Wang, Rongyao; Zhang, Xiangdong^*

来源：Nanoscale, 2017, 9(17): 5701-5707.

DOI：10.1039/c7nr01527e

• CHIRAL PLASMONIC NANOSTRUCTURES
• SURFACE-ENHANCED SPECTROSCOPIES
• CIRCULAR-DICHROISM
• SILICON NANOPARTICLES
• VISIBLE-LIGHT
• MAGNETIC RESPONSE
• METASURFACES
• RESONANCES
• SCATTERING
• FIELDS

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.

• 出版日期2017-5-7
• 单位北京理工大学; 昆明物理研究所