Application of nanocomposite materials in plasmon surface resonance spectroscopy

Abstract

The paper shows that nanocomposite materials based on a dielectric matrix with metal nanoparticles uniformly distributed in it can serve as a reference material in surface plasmon resonance spectroscopy. At certain concentrations of nanoparticles, such a nanocomposite, in contrast to the nanoparticles themselves, acquires the properties of a resonant material in which the real part of the complex permittivity takes negative values and, thus, the nanocomposite becomes surface-active. Surface plasmon polaritons can be excited at its boundary. For this reason, such a nanocomposite can be used as a reference material, similarly to the silver layer used, in the analysis of the optical properties of samples by surface plasmon resonance spectroscopy. The case of circular polarization of light incident on the structure under study is considered. The analysis of ellipsometric parameters of reflected light is carried out. The high sensitivity of the method is shown. In the range of incidence angles of 35° - 55°, the most pronounced angular dependence of the ellipsometry parameters is observed. Taking into account the analysis carried out, it is possible to suggest using these patterns in SPR spectroscopy to analyze materials in a structure containing a layer of the material under study and nanocomposites as reference elements, against which a sharp extremes of reflected light appears.