Physico-chemical nanomaterials science

Non-destructive depth profile reconstruction of the interface between biomolecules and carbon-based surface using angle-resolved XPS

Artemenko A.1, Babčenko O.1, Štenclová P.1, Ukraintsev E.1,2, Marton M.3, Vojs M.3, Wårgberg T.4, Kromka A.1
1 Institute of Physics of the Czech Academy of Sciences, Cukrovarnická 10, 16200 Prague 6, Czech Republic
E-mail: artemenko@fzu.cz
2 Faculty of Electrical Engineering, Czech Technical University in Prague, Technická 2, 16627 Prague 6, Czech Republic 
3Institute of Electronics and Photonics, Slovak University of Technology, Ilkovičova 3, SK-812 19 Bratislava, Slovakia
4Department of Physics, Umeå University, Linnaeus väg 24, Umeå 90187, Sweden

Carbon-based materials such as nanocrystalline diamond (NCD) and diamond-like carbon (DLC) are known as a promising platform for the development of tunable biomolecular interfaces. However, it is a challenge to make a proper modification of their surfaces and control the adhesion of biomolecules on them. Obviously, an understanding of actual mechanisms of interactions of biomolecules with carbon-based surfaces requires advanced surface analysis of the interface between organic/inorganic material.
Here we report on investigations of the interaction of various biomolecules with H- or O-functionalized NCD and DLC films using XPS. The depth distribution (<10 nm) of bonding states was calculated from the angular-resolved XPS spectra, i.e. the in-depth reconstructions of the bonding states at the interface between carbon-based materials and biomolecules. The in-depth distributions of the resolved bonding states revealed the dependence of oxygen-containing groups and C-N bonds from biomolecules on the surface termination of carbon-based materials. The XPS analysis was accompanied by other comprehensive methods like FTIR, AFM, SEM and WCA. The correlation between the obtained results will be discussed. 
The work is supported by Operational Programme Research, Development and Education financed by European Structural and Investment Funds and the Czech Ministry of Education, Youth and Sports (Project No. CZ.02.2.69/0.0/0.0/18_053/0016627), by project VEGA 1/0554/20 and by the Czech Science Foundation (project No. 20-00925Y).