Sculpted substrates for SERS

Abstract

Sculpted SERS-active substrates are prepared by assembling a closed packed monolayer of uniform polystyrene colloidal particles (diameter 350 to 800 nm) onto an evaporated gold surface and then electrodepositing gold through this template to produce films with controlled thicknesses, measured as fractions of the sphere diameter, d. The resulting surfaces consist of a regular hexagonal array of interconnected spherical cross-section dishes. The role of localised plasmons in determining the SERS enhancement factor obtained for benzene thiol adsorbed onto the surfaces is then investigated by correlation of the UV-visible reflectance spectra, 400 to 900 nm, measured at the same positions on the substrate surfaces, with the SERS spectra. The results are interpreted in terms of the relative contributions of plasmons that are free to propagate across the top surface and those trapped within the dishes of the sculpted surface.

Self-assembled nanoparticle arrays for multiphase trace analyte detection

“…Increasing the signal strength further can be achieved by tailoring the metallic substrate, thereby lowering the limits of detection. Of particular note, are two-dimensional arrays of closely packed metallic nanoparticles (NPs) on a substrate 18 or metallic nanocavities [19][20][21] . These benefit from multiple hot spots being generated in a uniform fashion over a larger substrate area generating high signal enhancement 22 throughout the entire substrate.…”

Fabrication of Arrays of Metal and Metal Oxide Nanotubes by Shadow Evaporation

“…Thus, we sought to study the SERS characteristics of arrays of Au nanotubes. Although there are many approaches for fabricating SERS substrates (e.g., embossing, colloidal lithography, e-beam lithography, electrochemical surface roughening), [54][55][56][57][58][59] the fabrication method presented here is advantageous because it provides a simple route to producing dense arrays of uniform, thin-walled (ϳ10 nm thick), metallic nanostructures over a large area (cm 2 ).…”

Capturing Irradiation with Nanoantennae: Plasmon‐Induced Enhancement of Photoelectrolysis

“…Previous works demonstrated that optimal SERS signals using a 633 nm laser were obtained for benzene-thiol adsorbed on SSV substrates using D = 600 nm diameter PS, in which the deposition height was 0.8D, i.e. a height of 480 nm 85,86 . The size of the surface cavity was 480 nm with 55 an inner diameter of 600 nm.…”

“…This makes the SERS intensity highly dependent on the cavity diameter and height and the resulting plasmonic modes 55,62,85 . The annealing temperature also influences the intensity of Raman bands, typically increasing with temperature as the crystallinity improves [122][123][124][125] .…”