An acoustically enhanced gold film Raman sensor on a lithium niobate substrate

Abstract

The surface enhanced Raman scattering effect has shown immense potential for detecting trace amounts of explosive vapor molecules. To date, efforts to produce a commercially available, reliable SERS sensor have been impeded by an inability to separate the electromagnetic enhancement produced by the metallic nanostructure from other signal enhancing effects. Here, we show a new Raman sensor that uses surface acoustic waves (SAWs) to produce controllable surface structures on gold films deposited on LiNbO3 substrates that modulate the Raman signal of a target compound (thiophenol) adsorbed on the films. We demonstrate that this sensor can dynamically control the Raman signal simply by changing the SAW's amplitude, allowing the Raman signal enhancement factor to be directly measured with no variation in the concentration of the target compound. The physically adsorbed molecules can be removed from the sensor without physical cleaning or damage, making it possible to reuse it for real‐time Raman detection. Copyright © 2014 John Wiley & Sons, Ltd.

Recent advances in linear and non‐linear Raman spectroscopy. Part IX

“…describe a new Raman sensor that uses surface acoustic waves (SAWs) to produce controllable surface structures on gold films deposited on LiNbO 3 substrates that modulate the Raman signal of a target compound (in this case thiophenol) adsorbed on the films. The physi‐adsorbed molecules can be removed from the sensor without physical cleaning or damage, making it possible to reuse it for real‐time Raman detection . Leordean and corwokers reported multiscale electromagnetic SERS enhancement on self‐assembled micropatterned gold nanoparticle films, and found that the multiplicative enhancement effect is obtained by combining surface plasmon near‐field enhancement because of nanoscale features with far‐field photonic coupling by periodic microscale features .…”