Aspect ratio dependence on surface enhanced Raman scattering using silver and gold nanorod substrates

Abstract

Silver and gold nanorods with aspect ratios from 1 to 16 have been used as substrates for surface enhanced Raman spectroscopy (SERS) in colloidal solution. The nanorod aspect ratio is varied to give different degrees of overlap between the nanorod longitudinal plasmon band and excitation source in order to determine its effect on overall surface enhancement. Results suggest that enhancement factors are a factor of 10-10(2) greater for substrates that have plasmon band overlap with the excitation source than for substrates whose plasmon bands do not.

Engineering the synthesis of silica–gold nano-urchin particles using continuous synthesis

“…12,18,19,20,21,22 Gold nanostructures, such as nanorods, nanowires, tetrapods, nanoplates and star-shaped particles are particularly attractive for many applications because of their strong confinement of the electromagnetic field and high enhancement that can be tuned over a wide range of optical wave lengths in comparison with ordinary spherical structures. 11,[23][24][25][26][27] Combination of the metal nanostructure with a support material, such as in core-shells, raspberries, and crescents, affords additional advantages in tuning optical properties, improved chemical/mechanical stability, and ease of handling compared to free-standing nanoparticles.Batch methods, 20 specialized ligands 28 and additional electrochemical treatments 29 have typically been needed to synthesize these optical architectures, but create challenges in achieving desired optical properties and sufficient reproducibility. Herein we develop a method based on molecular self-assembly and reduction chemistry of gold species to grow gold nanobranches on the surface of silica nanoparticles.…”

Coherent Plasmon-Exciton Coupling in Silver Platelet-J-aggregate Nanocomposites

“…These efforts have resulted in reliable methods for the fabrication of plasmonic nanorods, nanocubes, nanostars, and nanoplatelets. [17][18][19][20] Cyanine dyes are another class of materials that have been extensively studied, due to their use in spectral sensitization and potential applications in novel optoelectronic materials. These dyes have a tendency to aggregate under reduced solubility conditions or when adsorption occurs on particle or substrate surfaces.…”

Combined Antenna and Localized Plasmon Resonance in Raman Scattering from Random Arrays of Silver-Coated, Vertically Aligned Multiwalled Carbon Nanotubes

“…[10][11][12] In recent years silver and gold nanowires grown in porous alumina substrates have attracted interest as potential SERS substrates on account their plasmon-active nature. [13][14][15][16][17][18] In the context of carbon nanotube applications, very significant effort has been directed toward nanotube functionalization. 19 This can involve a wide range of treatments, typically with a view to the attachment of a species of interest 20 or to modification of the band structure (of single-walled nanotubes) for electronic device applications.…”