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Surface‐Enhanced Raman Spectroscopy for the Detection of a Metabolic Product in the Headspace Above Live Bacterial Cultures
Author(s) -
Kelly Jessica,
Patrick Robin,
Patrick Sheila,
Bell Steven E. J.
Publication year - 2018
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201808185
Subject(s) - detection limit , metabolite , bacteria , chemistry , raman spectroscopy , dimethyl disulfide , bacterial growth , dimethyl sulfide , nanoparticle , chromatography , nuclear chemistry , sulfur , biochemistry , nanotechnology , biology , materials science , organic chemistry , genetics , physics , optics
In situ surface‐enhanced Raman spectra of the headspace above cultures of six bacterial species showed strong characteristic bands from chemisorbed methyl sulfide. This marker compound is created by dissociation of dimethyl disulfide (DMDS), a fermentative metabolite of bacteria, on the surface of the enhancing Au or Ag nanoparticle films. Kinetic binding plots of media spiked with DMDS and of live cultures showed that the Au‐based substrates were more suitable for the rapid detection of bacteria than Ag‐based substrates. For E. coli DH5α, the sensitivity limit for headspace SERS detection was 1.5×10 7 CFU mL −1 , which corresponded to detection 15 min after inoculation of the growth medium. Since the metabolites are only produced by viable bacteria, antibiotic (gentamicin) treatment stopped the normal signal growth of the marker peak. This work is a promising step towards rapid bedside detection of bacterial infections and rapid screening of antibiotics against bacteria.