Lopatynskyi A. Optical response peculiarities in optoelectronic biosensors based on surface plasmon resonance

The thesis is devoted to study of optical response formation processes for multilayer thin-film structures (sensitive elements of surface plasmon-polariton resonance (SPPR) biosensor) under external factors influence and multilayer nanoscale core-shell structures (sensitive elements of localized surface plasmon resonance (LSPR) biosensor) depending on their geometrical and optical parameters, and also to development of portable biosensor model for biomolecular detection and real-time biomolecular reaction kinetics registration. The device was based on LSPR phenomenon in gold nanoparticles and core-shell nanostructures. The model for estimation of SPPR sensor optical response on external electrical potential application to gold-electrolyte interface was developed. Dependence of biomolecules adsorption extent in SPPR biosensor on the value of applied electric potential was discovered. New approach for modelling the optical response of LSPR biosensor based on spherical gold nanoparticles was developed. New model for calculation of extinction spectrum wavelength shift was demonstrated to achieve maximal LSPR response. Enhancement of extinction spectrum peak maximum position shift from 2 to 15 times was discovered upon the approach of LSPR peak in nanoparticle extinction spectrum and peak in absorption spectrum of the coating in comparison with the case, when these resonant peaks are mutually spaced along the wavelength scale. Gold nanoparticle aggregation extent was shown to depend on chemical structure and charge of analyte molecule and new model for gold nanoparticle colloid solution aggregative state was developed. Ordered gold nanostructure arrays produced by nanoimprint lithography were demonstrated to support LSPR excitation and to serve as LSPR biosensor sensitive elements in the incident light wavelength range from 600 to 1000 nm, which is regulated by nanostructure geometrical parameters and incident light polarization. Model of LSPR sensor device "NanoPlasmon-003" was fabricated, which allows carrying out measurements of nanoparticles colloid solutions in standard spectrophotometric cuvettes and nanostructure arrays on glass chips, especially in flow mode.