Plasmon Modes Hybridization Influence on Nano-Bio-Sensors Specification

In this paper, the interaction between surface plasmon resonance and fluorescence of the dye molecule is investigated and simulated. Due to the severe change of the nanoparticle-dye system´s optical properties, it can be used in the important biomedical applications. The presence of a nanoparticle in the surface plasmon resonance state locally concentrates electromagnetic waves of the incident field and can increase the absorption and emission fluorescence of a dye molecule (as adding an antenna to a receiver). Therefore, the motivation of this study is the use of the nanoparticle´s plasmon hybridization modes to reach to the highest near-field augmentation which is essential to the improvement of the dye´s lifetime and its quantum efficiency for deep-tissue imaging which dramatically need augmentation of the dye´s emitted photon. Specifically, we have investigated some nanoparticles which have a strong plasmon resonance to extend into visible to near-infrared spectra. Furthermore, the splitting of the surface plasmon into two distinctive modes as a result of the difference in polarization between the nanoparticle´s outer and inner surface are probed. We utilize Si/SiO₂/Ag as a novel proposal of core/shell nanoparticle for the emission enhancement of weak emitting fluorophores. The fluorescent enhancement of dye molecules as a function of distance from the nanoparticle´s surface, NPs´ radius, and spacer thickness between the inner and outer shell is studied.