SERS characterization of aggregated and isolated bacteria deposited on silver-based substrates.

SERS characterization of aggregated and isolated bacteria deposited on silver-based substrates. Anal Bioanal Chem. 2021 Jan 03;: Authors: Andrei CC, Moraillon A, Larquet E, Potara M, Astilean S, Jakab E, Bouckaert J, Rosselle L, Skandrani N, Boukherroub R, Ozanam F, Szunerits S, Gouget-Laemmel AC 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 so...
Source: Analytical and Bioanalytical Chemistry - Category: Chemistry Authors: Tags: Anal Bioanal Chem Source Type: research