Fiber-optic plasmonic probe with nanogap-rich Au nanoislands for on-site surface-enhanced Raman spectroscopy using repeated solid-state dewetting

J Biomed Opt. 2019 Mar;24(3):1-6. doi: 10.1117/1.JBO.24.3.037001.

Abstract

We report a fiber-optic plasmonic probe with nanogap-rich gold nanoislands for on-site surface-enhanced Raman spectroscopy (SERS). The plasmonic probe features nanogap-rich Au nanoislands on the top surface of a single multimode fiber. Au nanoislands were monolithically fabricated using repeated solid-state dewetting of thermally evaporated Au thin film. The plasmonic probe shows 7.8 × 106 in SERS enhancement factor and 100 nM in limit-of-detection for crystal violet under both the excitation of laser light and the collection of SERS signals through the optical fiber. The fiber-through measurement also demonstrates the label-free SERS detection of folic acid at micromolar level. The plasmonic probe can provide a tool for on-site and in vivo SERS applications.

Keywords: fiber optics; nanofabrication; plasmonics; solid-state dewetting; surface-enhanced Raman spectroscopy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Equipment Design
  • Fiber Optic Technology / instrumentation*
  • Folic Acid / analysis
  • Gold / chemistry*
  • Limit of Detection
  • Nanostructures / chemistry*
  • Nanotechnology / instrumentation
  • Nanotechnology / methods*
  • Signal Processing, Computer-Assisted
  • Spectrum Analysis, Raman / instrumentation*
  • Spectrum Analysis, Raman / methods

Substances

  • Gold
  • Folic Acid