Author

Neva Agarwala

Date of Graduation

Spring 2017

Degree

Master of Science in Materials Science

Department

Physics, Astronomy, and Materials Science

Committee Chair

Maria Stepanov

Keywords

HeLa cells, yeast cells, Raman spectroscopy, SERS, molecular vibrations, DFT calculations, oxidized graphene, functionalized graphene

Subject Categories

Materials Science and Engineering

Abstract

Raman spectroscopy is an important tool of molecular characterization based on inelastic scattering of monochromatic light by molecules. Since Raman spectra reflect unique vibrational properties of materials, the method offers a potential of selective molecular identification. Furthermore, surface-enhanced Raman spectroscopy (SERS) also is capable of a high sensitivity, since inelastic scattering of light from the molecules is strongly enhanced when Raman-active molecules are located close to roughened noble metal surfaces. In this thesis, Raman characterization protocols of liquid biological samples are optimized. Raman spectra of two different cell cultures, yeast cells and HeLa cells, were collected and interpreted. The potentiality of SERS enhancement was tested for the cell cultures on substrates containing a plasmonic-active layer. To facilitate interpretation of Raman spectra, water-soluble carbon based materials such as graphene oxide and fullerenol also are characterized, and these results were compared with predictions of the density-functional theory. These studies have demonstrated a proof-of-principle Raman characterization of cell cultures, suggested their spectral band assignments, elucidated differences and similarities in Raman bands between the cell cultures studied, and achieved a pronounced SERS enhancement for HeLa cell analysis.

Copyright

© Neva Agarwala

Open Access

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