Super-structured material-based surface-enhanced infrared substrate and molecule detection method thereof

Abstract

The invention discloses a super-structured material-based surface-enhanced infrared substrate and a molecule detection method thereof. The infrared substrate is sequentially provided with a support substrate, a uniform surface plasmon film, and a periodic array. By regulating the period of the periodic array, the uniform surface plasmon film of the infrared substrate and an electric dipole mode are coupled to each other, so that the resonance wavelength of the latter changes, and the near-field electric field strength increases. When a molecule to be measured is absorbed or prepared on the infrared substrate, a surface-enhanced infrared absorption spectrum of the molecule to be measured can be tested through external infrared spectroscopic equipment. The uniform surface plasmon film is made of a metal material or a dielectric material whose real part of the dielectric constant is negative, and the thickness is greater than 200nm. The detection method comprise the following steps of (1)acquisition of an experimental test spectrum; (2) acquisition of a theoretical simulation spectrum; (3) construction of an evaluation function; (4) inversion solution; and (5) result analysis.

Description

technical field [0001] The invention relates to the technical field of molecular detection, in particular to a metamaterial-based surface-enhanced infrared substrate and a molecular detection method thereof. Background technique [0002] Surface-enhanced spectroscopy utilizes near-field enhancement near rough surfaces or rationally designed metamaterial structures to enhance the scattered or reflected signals of attached molecules, thereby significantly improving the detection limit, even down to the single-molecule level. Since most molecules have their characteristic absorption fingerprints in the infrared wavelength range, infrared spectroscopy has become one of the most effective methods for identifying unknown organic species, which is called surface-enhanced infrared absorption spectroscopy (SEIRA). Therefore, SEIRA provides a powerful and reliable tool to detect trace molecules, as well as to study molecular conformational changes and molecular interactions. [0003]...

AI Technical Summary

Problems solved by technology

[0009] However, most of the above-mentioned methods involving optical constants have complex test procedures and low measurement accuracy, and because the molecular fingerprint vibration itself is very weak, it is difficult to achieve effective and reliable inversion of molecular optical constants, and only the real part of optical constants can be detected, which is difficult to accurately detect Imaginary part of optical constant

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