SERS characterization of aggregated and isolated bacteria deposited on silver-based substrates.
Anal Bioanal Chem
; 413(5): 1417-1428, 2021 Feb.
Article
em En
| MEDLINE
| ID: mdl-33388848
ABSTRACT
Surface-enhanced Raman scattering (SERS), based on the enhancement of the Raman signal of molecules positioned within a few nanometres from a structured metal surface, is ideally suited to provide bacterial-specific molecular fingerprints which can be used for analytical purposes. However, for some complex structures such as bacteria, the generation of reproducible SERS spectra is still a challenging task. Among the various factors influencing the SERS variability (such as the nature of SERS-active substrate, Raman parameters and bacterial specificity), we demonstrate in this study that the environment of Gram-positive and Gram-negative bacteria deposited on ultra-thin silver films also impacts the origin of the SERS spectra. In the case of densely packed bacteria, the obtained SERS signatures were either characteristic of the secretion of adenosine triphosphate for Staphylococcus aureus (S. aureus) or the cell wall and the pili/flagella for Escherichia coli (E. coli), allowing for an easy discrimination between the various strains. In the case of isolated bacteria, SERS mapping together with principal component analysis revealed some variabilities of the spectra as a function of the bacteria environment and the bactericidal effect of the silver. However, the variability does not preclude the SERS signatures of various E. coli strains to be discriminated.
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Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Análise Espectral Raman
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Staphylococcus aureus
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Escherichia coli
Limite:
Humans
Idioma:
En
Revista:
Anal Bioanal Chem
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
França