Separation of Electromagnetic and Chemical Contributions to Surface-Enhanced Raman Spectra on Nanoengineered Plasmonic Substrates
Semion K Saikin, Yizhuo Chu, Dmitrij Rappoport, Kenneth B Crozier, Alan Aspuru-Guzik
Journal of Physical Chemistry Letters | AMER CHEMICAL SOC | Published : 2010
Raman signals from molecules adsorbed on a noble metal surface are enhanced by many orders of magnitude due to the plasmon resonances of the substrate. Additionally, the enhanced spectra are modified compared to the spectra of neat molecules; many vibrational frequencies are shifted, and relative intensities undergo significant changes upon attachment to the metal. With the goal of devising an effective scheme for separating the electromagnetic and chemical effects, we explore the origin of the Raman spectra modification of benzenethiol adsorbed on nanostructured gold surfaces. The spectral modifications are attributed to the frequency dependence of the electromagnetic enhancement and to the..View full abstract
Awarded by Defense Advanced Research Project Agency
Awarded by Defense Threat Reduction Agency
This work was supported by the Defense Advanced Research Project Agency under Contract No. FA9550-08-1-0285 and the Defense Threat Reduction Agency under Contract No. HDTRAI-10-1-0046. We would like to thank the High Performance Technical Computing Center at the Faculty of Arts and Sciences of Harvard University and the National Nanotechnology Infrastructure Network Computation project for providing the computational resources.