Simultaneous Surface-Enhanced Raman Scattering with a Kerr Gate for Fluorescence Suppression

Gema Cabello; Igor V Sazanovich; Ioannis Siachos; Matthew Bilton; Beata L Mehdi; Alex R Neale; Laurence J Hardwick

doi:10.1021/acs.jpclett.3c02926

Simultaneous Surface-Enhanced Raman Scattering with a Kerr Gate for Fluorescence Suppression

J Phys Chem Lett. 2024 Jan 18;15(2):608-615. doi: 10.1021/acs.jpclett.3c02926. Epub 2024 Jan 10.

Authors

Gema Cabello^{1

2}, Igor V Sazanovich³, Ioannis Siachos⁴, Matthew Bilton⁵, Beata L Mehdi⁴, Alex R Neale^{1

2}, Laurence J Hardwick^{1

2}

Affiliations

¹ Stephenson Institute for Renewable Energy, Department of Chemistry, University of Liverpool, Peach Street, Liverpool L69 7ZF, U.K.
² The Faraday Institution, Quad One, Harwell Science and Innovation Campus, Didcot OX11 0RA, U.K.
³ Central Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 OQX, U.K.
⁴ Department of Mechanical Materials and Aerospace Engineering, University of Liverpool, Brownlow Hill, Liverpool L69 3GH, U.K.
⁵ SEM Shared Research Facility, University of Liverpool, Brownlow Hill, Liverpool L69 3GH, U.K.

Abstract

The combination of surface-enhanced and Kerr-gated Raman spectroscopy for the enhancement of the Raman signal and suppression of fluorescence is reported. Surface-enhanced Raman scattering (SERS)-active gold substrates were demonstrated for the expansion of the surface generality of optical Kerr-gated Raman spectroscopy, broadening its applicability to the study of analytes that show a weak Raman signal in highly fluorescent media under (pre)resonant conditions. This approach is highlighted by the well-defined spectra of rhodamine 6G, Nile red, and Nile blue. The Raman spectra of fluorescent dyes were obtained only when SERS-active substrates were used in combination with the Kerr gate. To achieve enhancement of the weaker Raman scattering, Au films with different roughnesses or Au-core-shell-isolated nanoparticles (SHINs) were used. The use of SHINs enabled measurement of fluorescent dyes on non-SERS-active, optically flat Au, Cu, and Al substrates.