Metallic Nanoparticle Arrays: A Common Substrate for Both Surface-Enhanced Raman Scattering and Surface-Enhanced Infrared Absorption

Abstract

Nanoshell arrays have recently been found to possess ideal properties as a substrate for combining surface enhanced raman scattering (SERS) and surface enhanced infrared absorption (SEIRA) spectroscopies, with large field enhancements at the same spatial locations on the structure. For small interparticle distances, the multipolar plasmon resonances of individual nanoshells hybridize and form red-shifted bands, a relatively narrow band in the near-infrared (NIR) originating from quadrupolar nanoshell resonances enhancing SERS, and a very broadband in the mid-infrared (MIR) arising from dipolar resonances enhancing SEIRA. The large field enhancements in the MIR and at longer wavelengths are due to the lightning-rod effect and are well described with an electrostatic model.

Core-shell Au-Ag nanoparticles in dielectric nanocomposites with plasmon-enhanced fluorescence: A new paradigm in antimony glasses

“…This is because the surface plasmon waves (surface plasmon polaritons) generated by electronic oscillations (SPR) travel along the surface of the metal NPs, concentrate light in the subwavelength structures due to the difference in relative permittivity of the metal and the surrounding glass matrix [15,16]. Concentration of light and effect of metallic screening lead to amplifi cation of the local electric field around the metal nanostructures (by "Lightning Rod Effect") with respect to the incident field [15]. Thus, the metal NPs provide a unique opportunity to modify the fluorescence due to changes in the rates of excitation and emission of RE ions.…”

“…Electromagnetic excitations are known to induce surface charges. The local surface charge densities are severely increased and confined near the sharp edges of anisotropic nanostructures which act as light-harvesting nano optical antennas converting visible light into large localized electric field ("lightning-rod effect") [15]. Therefore, quasispherical Au Ag nanostructures with sharp edges (see Fig.…”

“…Consequently, an emerging application of metal glass nanocomposites in the field of plasmonics is their development as substrates (hosts) capable of providing large electromagnetic enhancements or "hot spots" formation for surfaceenhanced spectroscopies of rare-earth ions [12 14]. Such enhanced local field properties originates due to surface plasmon resonance (SPR) in metallic nanostructures which is the collaborative oscillations of the free conduction band electrons on the metal surface on resonant excitation with electromagnetic radiation (light) [15,16]. The surface plasmon enhanced luminescence observed in monometallic: rare-earth (RE) hybrid composites have currently captured exponential attention due to their relevance as color displays, optical amplifi ers as well as optical sensors [12 14].…”

Surface-Enhanced Infrared Spectroscopy Using Metal Oxide Plasmonic Antenna Arrays

“…1 Au antennas have been shown to produce a strong SEIRS response. [21][22][23][24][25][26][27][28][29] For the SEIRS experiments, we used a thin, 50-nm layer of PMMA which was spincoated onto the antenna arrays. The presence of the PMMA can be observed in Fig.…”

Regioselective Localization and Tracking of Biomolecules on Single Gold Nanoparticles

“…A consequence of the interaction is the ability to concentrate light fields with orders of magnitude enhancement at visible and near infrared (NIR) wavelengths to the subwavelength scale. Such enhancements find profound applications in improving the efficiencies of several phenomena such as fluorescence,1, 2, 3 surface‐enhanced Raman spectroscopy (SERS),4, 5, 6, 7, 8 surface‐enhanced infrared absorption,9, 10, 11 single‐molecule detection,12, 13 nonlinear optical effects,14, 15, 16 and multiphoton polymerization 17, 18. Exploiting this highly confined optical field is crucial, but simultaneously it is also challenging to position the desired molecules or particles accurately at these locations.…”