Dresden 2009 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 23: Electronic and Optical Properties

CPP 23.5: Vortrag

Mittwoch, 25. März 2009, 15:00–15:15, ZEU 114

Oscillator strength of the peptide bond resonances at the C 1s and N 1s X-ray absorption thresholds — •Kurt Kummer¹, Victor Sivkov², Denis Vyalikh¹, Serguei Nekipelov², Anja Blüher³, Michael Mertig³, and Serguei Molodtsov¹ — ¹Institute of Solid State Physics, Dresden University of Technology, D-01062 Dresden, Germany — ²Komi Science Center, Russian Academy of Science, Ural Division, Syktyvkar 167982, Russia — ³BioNanotechnology and Structure Formation Group, Max Bergmann Center of Biomaterials and Institute of Materials Science, Technische Universität Dresden, D-01062 Dresden, Germany

X-ray absorption of regularly arrayed two-dimensional bacterial surface layers of bacillus sphaericus NCTC 9602 was investigated by means of total electron yield measurements. In doing so the spectral dependence of the total absorption cross section in the photon energy range between 280 and 580 eV was obtained, as well as partial absorption cross sections at the C 1s, N 1s and O 1s edges. At each of the three edges a sharp resonance originating in the peptide group showed up. For the very first time, the oscillator strengths of C 1s →π*(CONH) and the N 1s →π*(CONH) transitions were determined. Furthermore, we demonstrate that the folded structure of the protein leads to an increased oscillator strength of incorporated benzene rings when compared to free benzene molecules.