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Polarized Raman microspectroscopy on intact human hair
Author(s) -
Ackermann K. R.,
Koster J.,
Schlücker S.
Publication year - 2008
Publication title -
journal of biophotonics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.877
H-Index - 66
eISSN - 1864-0648
pISSN - 1864-063X
DOI - 10.1002/jbio.200810015
Subject(s) - raman microspectroscopy , raman spectroscopy , chemistry , nanotechnology , materials science , biophysics , optics , biology , physics
Polarization‐resolved Raman microspectroscopy with near‐infrared laser excitation was applied to intact human hair in order to non‐invasively investigate the conformation and orientation of the polypeptide chains. By varying the orientation of the hair shaft relative to the polarization directions of the laser/analyzer, a set of four polarized Raman spectra is obtained; this allows to simultaneously determine both the secondary structure of hair proteins and the orientation of the polypeptide strands relative to the axis of the hair shaft. For the amide I band, results from a quantitative analysis of the polarized Raman spectra are compared with theoretically expected values for fibers with uniaxial symmetry. Based on the polarization behavior of the amide I band and further vibrational bands, a partial ordering of α‐helical polypeptide strands parallel to the hair shaft can be concluded. We suggest that this microspectroscopic approach may be used for human hair diagnostics by detecting structural or orientational alterations of keratins. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)