[Zurück]

G. Ramer, A. Balbekova, A. Schwaighofer, B. Lendl:
"Method for Time-Resolved Monitoring of a Solid State Biological Film Using Photothermal Infrared Nanoscopy on the Example of Poly‑L‑lysine";
Analytical Chemistry, 87 (2015), S. 4415 - 4420.

We report time-resolved photothermal infrared
nanoscopy measurements across a spectral range of more than
100 cm−1 (1565 cm−1 to 1729 cm−1) at nanoscale spatial
resolution. This is achieved through a custom-built system using
broadly tunable external cavity quantum cascade lasers in
combination with a commercially available atomic force
microscope. The new system is applied to the analysis of
conformational changes of a polypeptide (poly-L-lysine) film
upon temperature-induced changes of the humidity in the film.
Changes of the secondary structure from β-sheet to α-helix could
be monitored at a time resolution of 15 s per spectrum. The
time-resolved spectra are well comparable to reference measurements
acquired with conventional Fourier transform infrared
microscopy.

http://dx.doi.org/10.1021/acs.analchem.5b00241