Coupled plasmonic systems: controlling the plasmon dynamics and spectral modulations for molecular detection

Abstract

A review on molecular detection using coupled plasmonic systems based on spectral modulations and further near-field enhancements.

Gold-iron oxide nanohybrids: insights into colloidal stability and surface-enhanced Raman detection

“…14 Since this time, multiple sensing applications have been derived from the surface-enhanced Raman (SERS) effect. [15][16][17][18] Especially gold particles have been in the focus of interest due to their superior stability compared to other noble metal nanoparticles such as silver or copper. 19 The SERS effect, which is caused by these noble metal nanomaterials, can be used to significantly improve the limit of detection for multiple molecules.…”

Graphene-Covered Silver Nanoisland Array Coupling with Hyperbolic Metamaterials for SERS Sensing

“…In multilayer HMMs, surface plasmon polaritons (SPP) resonating at the metal–dielectric interface between the layers formed BPPs highly confined to the HMM and could not propagate to the far field, , which is not favorable for SERS applications. Therefore, we use Gr/Ag Nis as an external coupling structure to achieve wave vector matching (Figure S1) and decouple the electric field bound within the HMM to the Ag Nis surface, thus generating a stronger electric field. , To examine the coupling effect of HMM and Gr/Ag Nis in the hybridized system, the reflectance spectra of the three structures (HMM, Gr/Ag Nis, and Gr/Ag Nis-HMM) were measured on silicon wafers, as presented in Figure d. In the spectral range of ∼300–1600 nm, the reflectance spectrum of the Gr/Ag Nis–HMM hybridized system changed significantly compared with HMM and Gr/Ag Nis structures and the reflectance of the sample decreased significantly in a wide range, which implies a corresponding increase in the absorption of light due to plasma resonance.…”

Plasmonic phenomena in molecular junctions: principles and applications

“…The coupling of plasmonic modes with molecular exciton states embedded in nanocavity junctions results in changes of the absorption spectra 108 , scattering 109 and surface-enhanced fluorescence 110 . The spectrum indicates how a plasmonic nanocavity couples with emitters, such as dyes and fluorescent molecules, and classifies the transition from weak to strong coupling 111,112 .…”

“…f | Normalized electric field distribution of the STM tip cavity shaped with a groove on the shaft, plotted on a logarithmic scale simulated for L = 3 μm at 610 nm. g | STML spectra measured over the silver (111) surface utilizing gold tips with grooves located at L = 3, 6 and 10 μm (V bias = 2.5 V, I t = 9 nA). L is the distance between the groove edge and the STM tip apex.…”