| AVS 66th International Symposium & Exhibition | |
| Biomaterial Interfaces Division | Tuesday Sessions |
| Session BI+AS-TuM |
| Session: | Characterization of Biological and Biomaterial Surfaces |
| Presenter: | Marit Kjaervik, Bundesanstalt für Materialforschung und -prüfung, Germany |
| Authors: | M. Kjaervik, Bundesanstalt für Materialforschung und -prüfung, Germany P. Dietrich, SPECS Surface Nano Analysis GmbH, Germany A. Thissen, SPECS Surface Nano Analysis GmbH, Germany K. Schwibbert, Bundesanstalt für Materialforschung und -prüfung, Germany W.E.S. Unger, Bundesanstalt für Materialforschung und -prüfung, Germany |
| Correspondent: | Click to Email |
Bacterial samples are typically freeze dried or cryo-prepared prior to XPS analysis to allow for measurements in ultra-high vacuum (UHV). The sample environment in the near-ambient pressure (NAP) XPS instrument EnviroESCA allows for measurements in up to 15 mbar water vapor, thus, sample preparation is no longer restricted to UHV-compatible techniques.[1] For instance, biofilms grown in medium can be transferred directly from the medium to the measurements chamber, maintaining a humid environment throughout the measurements.[2] Considering the complexity of bacterial samples, sample preparation must be carefully considered in order to obtain meaningful and reproducible results.
In this talk, various strategies for sample preparation of bacteria and biofilms for NAP-XPS measurements will be discussed. Model systems of planktonic bacteria, artificial biofilms resembling the exopolysaccharide matrix and biofilms have been characterised in various conditions. The stability and homogeneity of the samples were assessed by monitoring the C1s core-level peak at different sample locations. The quality of the XP spectra is also influenced by the gas environment, which will be exemplified by core level spectra of P. Fluorescens acquired in air, water vapor and ultra-high vacuum.
Furthermore initial results from iodine doped model biofilms will be presented. The in-depth chemcial compositon profile of these model films was obtained using an argon gas cluster ion gun.
Acknowledgements
This project has received funding from the EMPIR programme co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme.
[1] P. M. Dietrich, S. Bahr, T. Yamamoto, M. Meyer, and A. Thissen, “Chemical surface analysis on materials and devices under functional conditions – Environmental photoelectron spectroscopy as non-destructive tool for routine characterization,” J. Electron Spectros. Relat. Phenomena, vol. 231, pp. 118–126, Feb. 2019.
[2] M. Kjaervik, K. Schwibbert, P. Dietrich, A. Thissen, and W. E. S. Unger, “Surface characterisation of Escherichia coli under various conditions by near-ambient pressure XPS,” Surf. Interface Anal., vol. 50, no. 11, pp. 996–1000, Nov. 2018.