Chemical Sensing of Common Microorganisms Found in Biopharmaceutical
Industries Using Mid-Infrared Laser Spectroscopy and Multivariate
Analysis
Abstract
We report on the spectroscopic investigation of common bacteria
encountered in biopharmaceutical industries with spectroscopic
definition and specificity using mid-infrared laser spectroscopy. This
study describes the detection of three different bacteria species using
quantum cascade laser spectroscopy coupled to a grazing angle probe
(QCL-GAP). Stainless steel substrates were used as support for the
bacterial samples. QCL-GAP spectroscopy was assisted by multivariate
analysis (MVA) to assemble a powerful spectroscopic technique with
classification, identification, and quantification resources. The
bacterial species analyzed, Staphylococcus aureus,
Staphylococcus epidermidis, and Micrococcus luteus, were
used to challenge the technique’s capability to discriminate
microorganisms from the same family. Principal component analysis and
partial least squares-discriminant analysis differentiated between the
bacterial species using QCL-GAP. Spectral differences in the bacterial
membrane were used to determine if these microorganisms were present in
the samples analyzed. Results herein provided effective discrimination
for the bacteria under study with high sensitivity and specificity
values.