Chemical sensing of common microorganisms found in biopharmaceutical industries using MIR laser spectroscopy and multivariate analysis

Mid‐infrared laser spectroscopy was used to investigate common bacteria encountered in biopharmaceutical industries. The study involved the detection of bacteria using quantum cascade laser spectroscopy coupled to a grazing angle probe (QCL‐GAP). Substrates similar to surfaces commonly used in biopharmaceutical industries were used as support media for the samples. Reflectance measurements were assisted by Multivariate Analysis (MVA) to assemble a powerful spectroscopic technique with classification and identification resources. The species analyzed, Staphylococcus aureus, Staphylococcus epidermidis, and Micrococcus luteus, were used to challenge the technique's capability to discriminate from microorganisms of the same family. Principal Components Analysis and Partial Least Squares‐Discriminant Analysis differentiated between the bacterial species, using QCL‐GAP‐MVA as the reference. 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. A quantum cascade laser coupled to a Grazing Angle Probe produced high‐quality spectral information from Staphylococcus aureus, Staphylococcus epidermidis, and Micrococcus luteus. Although the bacteria under investigation belong to the same family, the spectral information was robust enough to discriminate the bacteria mixtures from the neat bacteria.