Femtosecond Infrared Laser Spectroscopy of Characteristic Molecular Vibrations in Bacteria in the 6-µm Spectral Range

The transmission spectra of femtosecond laser pulses in the mid-IR range (5–6.6 μm) were investigated of submonolayer of Staphylococcus aureus and Pseudomonas aeruginosa bacteria on a silicon plate in the region of characteristic absorption bands of proteins and lipids, as well as stationary spectra after irradiation. Invertible “translucence” of samples in the region of characteristic bands of bacteria and blue shift these bands indicating the destruction of hydrogen bonds were discovered. The possibility of inactivation of pathogenic bacteria by selective IR laser denaturation of functional proteins by resonance irradiation of low average power is discussed.