Suspended ultrathin three-dimensional double-layer chiral metasurface structure, preparation method and application thereof

Abstract

The invention relates to a preparation method of a suspended ultrathin three-dimensional double-layer chiral metasurface structure. The method comprises the following steps of: S1, coating the upper layer and the lower layer of a silicon nitride film window with an electron beam glue, and drying; S2, coating the electron beam glue with a conductive glue, and drying; S3, writing an array consisting of a plurality of rotationally symmetrical pattern units by adopting electron beam lithography, and developing, wherein the electron beam penetrates from the upper layer of the silicon nitride film window to the lower layer of the silicon nitride film window; S4, after developing is completed, evaporatingmetal materials on the upper layer and the lower layer of the silicon nitride film window in a vacuum evaporation manner; and S5, after vacuum evaporation is completed, stripping and washing the electron beam glue to obtain the suspended ultrathin three-dimensional double-layer chiral metasurface. According to the method for preparing the suspended double-layer metasurface structure through single electron beam lithography, the preparation process of a traditional double-layer metasurface is greatly simplified; and the metal blocks on the upper side and the lower side of the suspended ultrathin three-dimensional double-layer chiral metasurface structure can be in contact with a chiral molecule solution, so that the sensitivity of chiral molecule detection is greatly improved.

Description

technical field [0001] The invention relates to the technical field of chiral molecular detection, in particular to a suspended ultrathin three-dimensional bilayer chiral metasurface structure and its preparation method and application. Background technique [0002] Chirality exists widely in nature. If the mirror image of an object cannot coincide with the original object, it is called chirality. A chiral molecule and its mirror image structure are called enantiomers and have different physical and chemical properties. Many chiral pharmaceuticals must be prepared as a single enantiomer in high purity because the other enantiomer can be toxic to the organism. Therefore, the detection of chiral molecules has great research significance. At present, the traditional detection methods of chiral molecules mainly include circular dichroism, optical dispersion, helical dichroism and Raman optical rotation. The chiral signals obtained by the above methods are very weak, so the con...

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Problems solved by technology

The single-layer metasurface structure is often a two-dimensional chiral structure, and its own chirality is not high, so the chiral signal enhancement for chiral molecules is very limited. Although the multilayer metasurface has a strong chiral signal enhancement effect, its The preparation process is very complicated and often requires multiple electron beam lithography processes, which greatly increases the detection cost

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