| AVS 55th International Symposium & Exhibition | |
| Biological, Organic, and Soft Materials Focus Topic | Wednesday Sessions |
| Session BO+AS+BI-WeA |
| Session: | Advances in Surface Analytical Methods for Organic and Biological Interfaces |
| Presenter: | P. Koelsch, University Heidelberg, Germany |
| Authors: | P. Koelsch, University Heidelberg, Germany V. Kurz, University Heidelberg, Germany R. Schmidt, University Heidelberg, Germany C.L. Howell, University of Maine M. Grunze, University Heidelberg, Germany |
| Correspondent: | Click to Email |
Sum-frequency generation (SFG) spectroscopy has been employed to characterize a variety of biointerphases in extended spectral regions in aqueous environment. This contribution summarizes our recent SFG studies on DNA films, extracellular matrix compounds, switchable self assembled monolayers, and other biological molecules. Molecular level details revealed in these studies show that SFG offers the prospect of characterizing conformation, orientation and ordering of biological molecules at interfaces in situ. The technique of SFG spectroscopy is inherently surface specific having submonolayer resolution. Being an all-optical technique it can be operated in aqueous environment and even buried interfaces can be assessed. However, beside the obvious potential impact of SFG spectroscopy, to date, most studies of biological systems have only been performed in the CH and OH stretching vibration regions. This is related to the difficulties in generating tunable high energy light pulses with table top laser systems at the biologically relevant lower wavenumber region (amide and fingerprint) to gain SFG spectra with reasonable signal to noise ratios. In this contribution we show, that our broadband femtosecond SFG spectrometer provides spectral data in the amide I and fingerprint region in air and aqueous environment on a daily bases which opens the opportunity to characterize in situ orientation and conformation of a wider class of more complex biomolecules. We will summarize these biologically related SFG results and demonstrate the potential impact of this technique, also to introduce SFG spectroscopy as another method for examining biofilms ex situ and in situ.