The effective susceptibility concept. Implementation for nanocomposite systems and sensing

The main idea of the effective susceptibility concept consists in calculation of the linear response of the nanosystem as a single whole to the external field. The effective susceptibility is derived from a self-consistent integral equation for the local field. The electrodynamic interactions between embedded particles as well as interactions between the particles and matrix are taken into account. The optical response of the nanocomposite thin film with inhomogeneous distribution of inclusions across the film thickness is obtained. The sensitivity of the bandwidth, intensity and frequency of plasmon resonance to the change in shell thickness of modified gold nanoparticles caused by biospecific interactions at the surface of nanoinclusions are analyzed. The absorption profiles depending on the characteristics of the shell of nanoinclusions allow proposing the optical control method for the biospecific reactions at the surface of modified nanoinclusions.