Study of the Influence of Quantum Effects on Energy Absorption by Coated Plasmonic Nanoparticles Using the Discrete Sources Method

The influence of quantum effects on the absorption cross section of gold nanoparticles with a polymer coating is considered. Such layered structures are used as photothermal agents in the treatment of oncological formations. A modification of the discrete sources method is used for the study. Quantum effects in the plasmonic core are modelled on the basis of mesoscopic boundary conditions with Feibelman parameters, which allow for taking into account of such quantum effects as spatial nonlocality, displacement of the electron cloud relative to the metal surface, and Landau damping. As a result of the study, it has been established that by changing the geometry of the plasmonic core, it is possible to control the position of the maximum of the absorption cross section within the transparency window of biomaterials, whereas variation of its volume affects only the cross section amplitude. It is shown that accounting for the quantum effect leads to a shift of the absorption cross section maximum towards shorter wavelengths by 10–15 nm, as well as a slight decrease in its amplitude within 5 $$%$$ .