Facile Fabrication of High-Density Sub-1-nm Gaps from Au Nanoparticle Monolayers as Reproducible SERS Substrates

Shaorong Si, Wenkai Liang, Yinghui Sun, Jing Huang, Weiliang Ma, Zhiqiang Liang, Qiaoliang Bao, Lin Jiang

Research output: Contribution to journalArticleResearchpeer-review

145 Citations (Scopus)

Abstract

The fabrication of ultrasmall nanogaps (sub-1 nm) with high density is of significant interest and importance in physics, chemistry, life science, materials science, surface science, nanotechnology, and environmental engineering. However, it remains a challenge to generate uncovered and clean sub-1-nm gaps with high density and uniform reproducibility. Here, a facile and low-cost approach is demonstrated for the fabrication of high-density sub-1-nm gaps from Au nanoparticle monolayers as reproducible surface-enhanced Raman scattering (SERS) substrates. Au nanoparticles with larger diameters possess lower surface charge, thus the obtained large-area nanoparticle monolayer generates a high-density of sub-1-nm gaps. In addition, a remarkable SERS performance with a 1011 magnitude for the Raman enhancement is achieved for 120 nm Au nanoparticle monolayers due to the dramatic increase in the electromagnetic field enhancement when the obtained gap is smaller than 0.5 nm. The Au nanoparticle monolayer is also transferred onto a stretchable PDMS substrate and the structural stability and reproducibility of the high-density sub-1-nm gaps in Au monolayer films are illustrated. The resultant Au nanoparticle monolayer substrates with an increasing particle diameter exhibit tunable plasmonic properties, which control the plasmon-enhanced photocatalytic efficiency for the dimerization of p-aminothiophenol. The findings reported here offer a new opportunity for expanding the SERS application.

Original languageEnglish
Pages (from-to)8137-8145
Number of pages9
JournalAdvanced Functional Materials
Volume26
Issue number44
DOIs
Publication statusPublished - 22 Nov 2016
Externally publishedYes

Keywords

  • monolayers
  • reproducible fabrication
  • stretchable materials
  • surface-enhanced Raman scattering (SERS) substrates

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