Spectral SPR effect in thin films of high-conductive metals and features of SPR-biosensors implementation in chromatic mode

In this paper, we have evaluated the application of various types of highly conductive metals for implementing the effect of spectral surface plasmon resonance (SPR) within a visible spectrum range to achieve more efficient and productive registration of biomolecules in a liquid medium using tricolor RGB cameras. Thin films of gold, silver, copper, and aluminum, as well as a bimetallic coating of silver with a gold superlayer on a glass substrate, are considered. Detailed calculations of the spectral characteristics of reflection at SPR excitation in the Kretschmann geometry are performed, particularly when a thin dielectric film is formed on the metal surface that imitates a layer of biomolecules. For each of the specified metals, the width of the region of implementation of the full-fledged SPR effect in the visible range of the spectrum is determined, and the sensitivity of the optical response to the influence of an external dielectric layer is assessed.