EC-QC Laser Spectroscopy for Mid-IR Transmission Measurements of Proteins in Aqueous Solution

ALCARAZ, MIRTA R.; SCHWAIGHOFER, ANDREAS; KRISTAMENT, CHRISTIAN; BRANDSTETTER, MARKUS; GOICOECHEA, HÉCTOR C.; LENDL, BERNHARD

Viena

Conferencia; ICAVS 8-International Conference on Advanced Vibrational Spectroscopy; 2015

TUWien

We introduce a rugged setup for mid-IR transmission measurements of the protein amide I band in aqueous solution at large optical paths using an EC-QCL operated in pulsed mode combined with an advanced data processing protocol to overcome non-random fluctuations in single beam spectra inherent to EC-QCL emission curves. A custom-made temperature-controlled flow cell was designed to provide temperature stability. Characteristic spectral features of proteins with different secondary structures have been elucidated at concentrations as low as 2.5 mg/mL