  The strong coupling of plasmonic resonance modes in conductive pyramidal
nanoparticles leads to an increase in the density of free charges on the
surface. By ensuring plasmonic coupling in the pyramidal nanoparticle lattice,
the achieved field intensity is potentiated. At the same time, a strong
coupling between resonant modes is guaranteed, which results in the formation
of new hybrid modes. In this manuscript, we demonstrated a tunable double
anticrossing interaction that results from the interaction between two
Localized Surface Plasmon Resonance (LSPR) modes and a Surface Plasmon
Polariton (SPP) wave. The tuning is done as a function of the variation of the
angle of incidence of the input electric field. From the double anticrossing,
an increase in field intensity in a blue-shifted LSPR mode located in the red
wavelength region is observed. This demonstrates that at certain angles of
incidence, the intensity field obtained is strongly favored, which would be
beneficial for applications such as Surface Enhancement Raman Spectroscopy
(SERS). Nanoparticle-based lattices have been widely used for biosensor
applications. However, one of the major limitations of this type of device is
the low tolerance to high concentrations of biomolecules, which significantly
affects their performance. According to the studies carried out for this
manuscript, it was demonstrated that the implemented geometry allows for the
observation of an LSPR mode, which is responsible for the control and
synchronization of other perceived resonances. This mode remains almost
invariant when subjected to structural variations or changes in the angle of
incidence of the electric field. These characteristics eliminate the limitation
mentioned above, allowing for sensitivities 10^3 times higher than those
achieved in conventional systems based on LSPR used to detect P. brasiliensis
antigen.
