Substrate-Induced Fano Resonances of a Plasmonic Nanocube: A Route to Increased-Sensitivity Localized Surface Plasmon Resonance Sensors Revealed

Abstract

Symmetry-breaking introduced by an adjacent semi-infinite dielectric can introduce coupling and hybridization of the plasmon modes of a metallic nanostructure. This effect is particularly large for entities with a large contact area adjacent to the dielectric. For a nanocube, a nearby dielectric mediates an interaction between bright dipolar and dark quadrupolar modes, resulting in bonding and antibonding hybridized modes. The Fano resonance that dominates the scattering spectrum arises from the interference of these modes. This analysis provides a strategy for optimizing the sensitivity of nanostructures, whether chemically synthesized or grown by deposition methods, as high-performance localized surface plasmon resonance sensors.

Exciton-plasmon coupling interactions: from principle to applications

“…SPP can propagate between the medium and the surface of metal until the energy gradually disappear [134]. Having described the basics of SPPs in Section 2, a number of applications controlling their propagation in the context of waveguiding are emerged, such as SPR sensors [135], SERS [136], cloaking [137], and photothermal cancer therapy [138]. Nowadays, plasmonics applied in chemical reactions has aroused widespread concerns.…”

Unraveling the Evolution and Nature of the Plasmons in (Au Core)–(Ag Shell) Nanorods

“…The scaling-down technique has been proven to be effective in studying the eigenmodes of plasmon resonances, because it diminishes the damping and retardation effects caused by large nanocrystal sizes. [ 42 ] Figure 4 F shows the calculated extinction spectra of the small pure Ag cuboid excited under the LE, TE, and TD polarizations. Clearly, the LE-polarized light only excites the peak 1, and the other three peaks can be excited by the TE or TD polarization.…”

Heterodimer Nanostructures Induced Energy Focusing on Metal Film

“…Since the LSPR properties are greatly influenced by the size, shape, material and especially the plasmon coupling, various complex metal nanostructures has been investigated in the past, such as nanosphere 15 , nanocube 16 , nanorod 17 , nanowire 18 , nanorice 19 , coreshell nanostructure 20 , nanoarray 4 , nanoparticle dimer 15 , nanoparticle trimer 21 , etc. Among them, nanoparticle dimers for the simple fabrication become the oldest and most common configuration of metal nanostructure to understand the physical mechanism of LSPR, especially in the study of SERS 15,22 .…”