Surface-enhanced Raman Spectroscopy for Trace Identification of Controlled Substances: Morphine, Codeine, and Hydrocodone

Authors

  • Vinesh Rana M.A.,

    1. Department of Forensic Science, John Jay College of Criminal Justice, 445 West 59th Street, New York, NY 10019.
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  • Maria V. Cañamares Ph.D.,

    1. Department of Chemistry and Center for Study of Structures and Interfaces (CASI), The City College of New York, Convent Avenue at 138th Street, New York, NY 10031.
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  • Thomas Kubic Ph.D.,

    1. Department of Forensic Science, John Jay College of Criminal Justice, 445 West 59th Street, New York, NY 10019.
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  • Marco Leona Ph.D.,

    1. Department of Scientific Research, The Metropolitan Museum of Art, 1000 Fifth Avenue, New York, NY 10028.
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  • John R. Lombardi Ph.D.

    1. Department of Chemistry and Center for Study of Structures and Interfaces (CASI), The City College of New York, Convent Avenue at 138th Street, New York, NY 10031.
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Additional information and reprint requests:
Maria Vega Cañamares, Ph.D.
Department of Chemistry and Center for Study of Structures and Interfaces (CASI)
The City College of New York
Convent Avenue at 138th Street, New York, NY 10031
E-mail: maria.canamares@metmuseum.org

Abstract

Abstract:  We obtain the normal Raman and surface-enhanced Raman spectrum of three controlled substances: morphine, codeine, and hydrocodone. The spectra are assigned with the aid of density functional theory. Because of rather intense fluorescence, normal Raman spectra suffer from poor signal-to-noise, even when differential subtraction techniques are employed. On the other hand, surface enhancement by Ag nanoparticles both enhances the Raman signal and suppresses the fluorescence, enabling far more sensitive detection and identification. We also present a set of discriminant bands, useful for distinguishing the three compounds, despite the similarities in their structures.

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