Research On Ellipsometry Based On Hydrogel Film-Ultra-Thin Gold Film Combination

With the development of science and the advancement of preparation technology,researchers have designed a variety of sensing equipment and detection instruments based on the principles of optics,such as optical measuring instruments,laser interferometers,gratings,and optical fiber optical sensors and instruments.Due to the advantages of non-contact and non-destructive measurement,non-interference,high-speed transmission of information,and telemetry and remote control,optical sensors have been obtained in the fields of petroleum,electricity,biomedicine,mechanical transportation,aerospace,national defense research and information industry widely used.With the high precision and high sensitivity required for measurement and the complexity of the measurement environment,the environmental response characteristics and optical characteristics of thin film materials have gradually attracted the attention of scholars.Among them,hydrogel film materials are widely used in tissue engineering,drug release and control,etc.with non-toxic,water-absorbing swelling,self-healing and environmental response characteristics;effects,macroscopic quantum tunneling effects and dielectric confinement effects have attracted many scholars to explore and research,and have become a research hotspot in recent years.Commercial LSPR instruments have also gradually appeared on the market and are widely used in commercial applications.By combining thin-film materials with traditional optical sensing structures and developing new types of sensor devices,it is expected to solve the problem of high-sensitivity and high-precision sensing needs in different environmentsIn order to meet the needs of high-sensitivity and high-precision sensing in a complex detection environment,Chitosan is used as the raw material in this article,adds an initiator and a cross-linking agent,and reacts with acrylic acid to graft,chemically prepare a chitosan hydrogel and analyze the shell Swelling characteristics of glycan hydrogel,and carried out research on the optical properties of chitosan hydrogel,and analyzed the relationship between the refractive index of chitosan hydrogel and the changes of water absorption and wavelength under different swelling degrees;using gold as the target material,an ultra-thin nano-gold film with a thickness of 10nm was prepared by magnetron sputtering,the absorbance of the ultra-thin gold film was measured,and a four-layer film structure of air-gold nanoparticles-SiO₂-Si was established.The physical model of the method is based on the spectral ellipsometry method and the generalized effective medium approximation?EMA?proposed by Cohen et al.to carry out the characterization study of the complex dielectric constant of the ultra-thin gold film.The effects of local surface plasmon resonance?LSPR?and free electron?Drude?absorption;based on the combination of hydrogel film-ultra-thin gold film,combined with self-assembly technology and the principle of spectral ellipsometry,the preparation study of the ellipsometry sensor was carried out,and the sensor was used to sense and analyze the glucose concentration.The combination of sensors provides a theoretical basis.Through the analysis and research of the optical properties of optical thin film materials,it will lay the foundation for the development of new high-precision and high-sensitivity sensor devices for complex detection environments.