Evolutions towards a new LSPR particle: Nano-sinusoid Progress in Electromagnetic Research (PIER)

This paper proposes a novel nano-sinusoid particle to be employed in enhanced localized surface plasmon resonance (LSPR) bio-sensing devices. Numerical investigations are carried out to demonstrate advantages o®ered by the proposed nano-particle on LSPR enhancement over other nano-particles including noble nano-triangles and nano-diamonds. Although nano-triangles exhibit high concentration of the electric ¯eld near their tips, when illuminated with a light polarized along the tip axis, they present only one hot spot at the vertex along the polarization direction. To create a structure with two hot spots, which is desired in bio-sensing applications, two nano-triangles can be put back-to-back. Therefore, a nano-diamond particle is obtained which exhibits two hot spots and presents higher enhancements than nano-triangles for the same resonant wavelength. The main drawback of the nano-diamonds is the °uctuation in their physical size-plasmon spectrum relationships, due to a high level of singularity as the result of their four sharp tip points. The proposed nano-sinusoid overcomes this disadvantage while maintaining the bene¯ts of having two hot spots and high enhancements.