Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/219140

Title

Influence of electric field on SERS: frequency effects, intensity changes, and susceptible bonds

Author(s)

Sriram, Sharath;  Bhaskaran, Madhu;  Chen, Shijian;  Jayawardhana, Sasani;  Stoddart, Paul R.;  Liu, Jefferson Z.;  Medhekar, Nikhil V.;  Kalantar-Zadeh, Kourosh;  Mitchell, Arnan

Abstract

The fundamental mechanism proposed to explain surface-enhanced Raman scattering (SERS) relies on electromagnetic field enhancement at optical frequencies. In this work, we demonstrate the use of microfabricated, silver nanotextured electrode pairs to study, in situ, the influence of low frequency (5 mHz to 1 kHz) oscillating electric fields on the SERS spectra of thiophenol. This applied electric field is shown to affect SERS peak intensities and influence specific vibrational modes of the analyte. The applied electric field perturbs the polar analyte, thereby altering the scattering cross section. Peaks related to the sulfurous bond which binds the molecule to the silver nanotexture exhibit strong and distinguishable responses to the applied field, due to varying bending and stretching mechanics. Density functional theory simulations are used to qualitatively verify the experimental observations. Our experimental and simulation results demonstrate that the SERS spectral changes relate to electric field induced molecular reorientation, with dependence on applied field strength and frequency. This demonstration creates new opportunities for external dynamic tuning and multivariate control of SERS measurements.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Engineering and Industrial Sciences

Source

Journal of the American Chemical Society, Vol. 134, no. 10 (Mar 2012), pp. 4646-4653

Publication year

2012

FOR Code(s)

03 Chemical Sciences

Keyword(s)

Bonds;  Electric fields;  Frequency;  Intensity;  SERS;  Surface-enhanced Raman scattering

Publisher

American Chemical Society

ISSN

0002-7863

Publisher URL

http://dx.doi.org/10.1021/ja208893q

Copyright

Copyright © 2011 American Chemical Society.

Research Projects

Dynamic substrates for surface-enhanced Raman scattering: piezoelectric actuated nanotextures with phase-locked signal processing, Australian Research Council grant number DP110100262
Molecular spectroscopic 2D and 3D imaging systems at sub-micron spatial resolution, Australian Research Council grant number LE100100215
Complementary metal-oxide-semiconductor (CMOS)-compatible ultra-high response piezoelectric thin films for efficient energy harvesting, Australian Research Council grant number DP1092717

Peer reviewed