Optoplasmonic effects in highly curved surfaces for catalysis, photothermal heating, and SERS

Jean-Francois Masson, Gregory Q. Wallace, Jérémie Asselin, Andrey Ten, Maryam Hojjat Jodaylami, Karen Faulds, Duncan Graham, John S. Biggins, Emilie Ringe

Research output: Contribution to journalArticlepeer-review

1 Downloads (Pure)

Abstract

Surface curvature can be used to focus light and alter optical processes. Here, we show that curved surfaces (spheres, cylinders, and cones) with a radius of around 5 μm lead to maximal optoplasmonic properties including surface-enhanced Raman scattering (SERS), photocatalysis, and photothermal processes. Glass microspheres, microfibers, pulled fibers, and control flat substrates were functionalized with well-dispersed and dense arrays of 45 nm Au NP using polystyrene-block-poly-4-vinylpyridine (PS-b-P4VP) and chemically modified with 4-mercaptobenzoic acid (4-MBA, SERS reporter), 4-nitrobenzenethiol (4-NBT, reactive to plasmonic catalysis), or 4-fluorophenyl isocyanide (FPIC, photothermal reporter). The various curved substrates enhanced the plasmonic properties by focusing the light in a photonic nanojet and providing a directional antenna to increase the collection efficacy of SERS photons. The optoplasmonic effects led to an increase of up to 1 order of magnitude of the SERS response, up to 5 times the photocatalytic conversion of 4-NBT to 4,4′-dimercaptoazobenzene when the diameter of the curved surfaces was about 5 μm and a small increase in photothermal effects. Taken together, the results provide evidence that curvature enhances plasmonic properties and that its effect is maximal for spherical objects around a few micrometers in diameter, in agreement with a theoretical framework based on geometrical optics. These enhanced plasmonic effects and the stationary-phase-like plasmonic substrates pave the way to the next generation of sensors, plasmonic photocatalysts, and photothermal devices.
Original languageEnglish
Pages (from-to)46181–46194
Number of pages14
JournalACS Applied Materials and Interfaces
Volume15
Issue number39
Early online date21 Sept 2023
DOIs
Publication statusPublished - 4 Oct 2023

Keywords

  • microspheres
  • fibers
  • Raman
  • SERS
  • catalysis
  • microscopy
  • photothermal heating

Fingerprint

Dive into the research topics of 'Optoplasmonic effects in highly curved surfaces for catalysis, photothermal heating, and SERS'. Together they form a unique fingerprint.

Cite this