Planar SERS sensors for SARS-CoV-2 virus detection

Electrodynamic model of the radiation of molecules placed in a metal shell has been developed. The model qualitatively describes the secondary Raman radiation from protein globules coated with a thin silver film. The model makes it possible to calculate the change in the SERS signal depending on the thickness of the metal nanolayer over the protein globule. The radiating molecular dipole interacts with the metal shell and excites surface plasmons. Plasmon oscillations reach a maximum when the dipole frequency is close to the plasmon resonance of the metal envelope, and the dipole itself is located near the plasmon envelope.