Ultrathin Suspended Chiral Metasurfaces for Enantiodiscrimination. Issue 37 (17th August 2022)

• Record Type: Journal Article
• Authors: Cen, Mengjia; Wang, Jiawei; Liu, Jianxun; He, Huilin; Li, Ke; Cai, Wenfeng; Cao, Tun; Liu, Yan Jun
• Is Part Of: Advanced materials. Volume 34:Issue 37(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-08-17
• Subjects: biosensors -- circular dichroism -- suspended bilayer metasurfaces; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202203956
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Chiral metasurfaces can exhibit a strong circular dichroism, but it is limited by the complicated fabrication procedure and alignment errors. Here, a new type of self‐aligned suspended chiral bilayer metasurface with only one‐step electron beam lithography exposure is demonstrated. A significant optical chirality of 221° µm −1 can be realized using suspended metasurfaces with a thickness of 100 nm. Furthermore, this study experimentally demonstrates that such a structure is capable of label‐free discrimination of the chiral molecules at zeptomole level, exhibiting a much higher sensitivity (orders of magnitude) compared to the conventional circular dichroism spectroscopy. The fundamental principles for chiral sensing using molecules–metasurfaces interactions are explored. Benefiting from the giant chiroptical response, the proposed metadevice may offer promising applications for ultrathin circular polarizers, chiral molecular detectors, and asymmetry information processing. Abstract : A self‐aligned suspended chiral bilayer metasurface is developed with single‐step electron beam lithography. A huge optical chirality of 221° µm −1 is achieved by the freestanding metasurfaces with overall thickness of 100 nm. The bilayer metasurface demonstrates label‐free discrimination of chiral molecules at zeptomoles level with orders of magnitude larger than conventional circular dichroism spectroscopy.