DESIGN OF HYBRID PLASMONIC NANOPORES FOR ENGINEERED ELECTROMAGNETIC FIELD CONFINEMENT

This work presents a multiphysical study of processes in three-dimensional plasmonic and magneto-plasmonic nanopores. The distribution of the electromagnetic field, photothermal effects, ion transport, and the dynamics of nanoscale objects within nanopores were investigated in detail. The influence of nanopore geometry on the rectification of ion current, localization of plasmon modes, and distribution of the electromagnetic field has been studied. The simulation of plasmonic and hybrid Au/Si nanopores has been performed, and the photothermal effects arising from the absorption of electromagnetic radiation by the metallic part of the structure have been investigated. To analyze the enhancement of fluorescence in 3D plasmonic nanopores, we calculated the change in the overall decay rate of dipole radiation near a metal surface. We found that there is an optimal distance between the fluorophore and the plasmonic surface, determined by the balance between local field enhancement and non-radiative losses. The main part of the work is devoted to the study of a magneto-plasmonic trap for Fe₃O₄@Au nanoparticles in a magneto-plasmonic nanopore. A multiphysics approach was implemented, combining calculations of the electromagnetic field distribution, optical and magnetic traps, plasmonic heating, thermophoretic effects, and particle dynamics. It has been shown that the stability of the capture is determined by the competition between optical force, magnetic force, viscous resistance, and thermophoretic transport, and an increase in laser power can lead to thermophoretic destabilization of the capture mode. These results expand our understanding of plasmonic and magnetoplasmonic nanoporous systems and can be used in the development of nanopore-based biosensors, nanofluidic devices, and systems for controlled capture of nanoscale objects.