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First Nano-Infrared Spectroscopy and Imaging Measurements of Single Phospholipid Bilayers

preprint
revised on 25.02.2018 and posted on 26.02.2018 by Adrian Cernescu, Michał Szuwarzyński, Urszula Kwolek, Karol Wolski, Paweł Wydro, Mariusz Kepczynski, Magdalena Wytrwał-Sarna, Szczepan Zapotoczny, Maria Nowakowska, Luca Quaroni
Scattering-mode Scanning Near-Field Optical Microscopy (sSNOM) allows one to obtain absorption spectra in the mid-IR region for samples as small as 20 nm in size. This configuration has made it possible to measure FTIR spectra of the protein complement of membranes. (Amenabar 2013) We now show that mid-IR sSNOM has the sensitivity required to measure spectra of phospholipids in individual bilayers in the spectral range 800 cm-1–1400 cm-1. We have observed the main absorption bands of the dipalmitoylphosphatidylcholine headgroups in this spectral region above noise level. We have also mapped the phosphate absorption band at 1070 cm-1 simultaneously with the AFM topography. We have shown that we could achieve sufficient contrast to discriminate between single and multiple phospholipid bilayers and other structures, such as liposomes. This work opens the way to further research that uses nano-IR spectroscopy to describe the biochemistry of cell membranes and model systems.

Funding

European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 665778 (POLONEZ fellowship to LQ amnaged by the National Science Center Poland)).

History

Email Address of Submitting Author

luca.quaroni@uj.edu.pl

Institution

Jagiellonian University, Faculty of Chemistry, PL-30387, Kraków

Country

Poland

ORCID For Submitting Author

0000-0002-0225-9775

Declaration of Conflict of Interest

Adrian Cernescu is an employee of Neaspec Gmbh, which produces and sells the instrument used in this work. The other authors have no conflicts of interest.

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