Discrimination of bacteria and bacteriophages by Raman spectroscopy and surface-enhanced Raman spectroscopy

Lindsay J. Goeller, Mark R. Riley

Research output: Contribution to journalArticle

47 Scopus citations

Abstract

Detection of pathogenic organisms in the environment presents several challenges due to the high cost and long times typically required for identification and quantification. Polymerase chain reaction (PCR) based methods are often hindered by the presence of polymerase inhibiting compounds and so direct methods of quantification that do not require enrichment or amplification are being sought. This work presents an analysis of pathogen detection using Raman spectroscopy to identify and quantify microorganisms without drying. Confocal Raman measurements of the bacterium Escherichia coli and of two bacteriophages, MS2 and PRD1, were analyzed for characteristic peaks and to estimate detection limits using traditional Raman and surface-enhanced Raman spectroscopy (SERS). MS2, PRD1, and E. coli produced differentiable Raman spectra with approximate detection limits for PRD1 and E. coli of 10 9 pfu/mL and 10 6 cells/mL, respectively. These high detection concentration limits are partly due to the small sampling volume of the confocal system but translate to quantification of as little as 100 bacteriophages to generate a reliable spectral signal. SERS increased signal intensity 10 3 fold and presented peaks that were visible using 2-second acquisitions; however, peak locations and intensities were variable, as typical with SERS. These results demonstrate that Raman spectroscopy and SERS have potential as a pathogen monitoring platform.

Original languageEnglish (US)
Pages (from-to)679-685
Number of pages7
JournalApplied Spectroscopy
Volume61
Issue number7
DOIs
Publication statusPublished - Jul 1 2007

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Keywords

  • Bacteriophage
  • Pathogen detection
  • Raman spectroscopy
  • Surface-enhanced Raman spectroscopy

ASJC Scopus subject areas

  • Instrumentation
  • Spectroscopy

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