Enhanced thermoplasmonic oscillations in metallic nanostructured particles for the realization of nanofluidic sensors

We theoretically investigate the intense tunable nanofocusing of light in certain families of metallo-dielectric nanograin particles and topologically defected nanocylinders, mediated by thermoplasmonic resonances. By using versatile numerical algorithms, based on either exact 3-D electromagnetic scattering from canonical geometries, or discrete dipole approximation modeling for particles with arbitrary shapes, associated with the spectral as well as the thermooptical response of the proposed classes of plasmonic nanostructures, we identify the mechanisms responsible for the enhanced tunable thermoplasmonic resonances, by varying the ambient temperature. In addition it is found that the plasmonic resonances are also sensitive to the electric properties of the host medium, thus enabling this novel class of plasmonic nanoparticles to be used as fluidic (liquid/gas) sensors. Our investigation is expected to remove an essential obstacle in the development of nanosensing platforms with high sensitiveness to temperature fluctuations and ultracompact size, thus making the proposed plasmonic resonators excellent candidates for future nanoplasmonic sensing systems.