Applied Physical Chemistry

We are a highly interdisciplinary research group with a strong focus on the optical and electronic properties of carbon-based nanomaterials (mainly single-walled carbon nanotubes, SWCNTs) and organic semiconductors. We focus on processing, functionalization, characterization and application of these unconventional semiconductors for optoelectronic devices and sensors.

Please visit our new website:
https://www.pci.uni-heidelberg.de/en/zaumseil

Interaction of biomolecules with artificial surfaces / Chemical and biochemical sensors

The activities of the Biosensor and Biomaterials Research Group are focused on a detailed understanding of the interaction of biomolecules with artificial surfaces, which is important for many medical, biochemical and biotechnological applications. Inter alia, we investigate new methods for the specific detection of dissolved molecules, the mechanisms of joint lubrication, and the impact of physicochemical surface parameters on protein adsorption and function. In this context, not only homogeneous but also chemically micro- and nanostructured surfaces are of major interest. By the use of acoustic wave-based and optical sensors, adsorption and binding processes are monitored in situ without the necessity of labeling the molecules. One of our major goals is the label-free in situ analysis of biospecific interactions in high-density peptide arrays.

The derivatized surfaces are analyzed by surface analytical techniques such as infrared spectroscopy (FT-IRRAS, ATR-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), and enzyme-linked immunosorbent assays (ELISA). In addition, neutron and X-ray reflectometry is used to characterize solid/liquid interfaces as well as organic films and biological adsorbates. The investigations are directed towards a precise control of adsorption and binding processes via specific variation of surface properties.

Latest research focuses on the development of optically responsive nano-composite layers for the label-free in situ detection of binding events in high-density peptide arrays, the contribution of lipids and polysaccharides to joint lubrication, the control of protein conformation on synthetic surfaces, and the set-up of a new neutron reflectometer with integrated ATR-IR spectroscopy at the Helmholtz Center Berlin (HZB). The latter instrument has been optimized for the in situ characterization of biofunctional interfaces and is accessible to a large community of users.

Homepage Research Group: Biosensors and Biomaterials

Contact: Reiner Dahint

Surface science and analytics

The main focal points of the Surface Science & Analytics group are (1) basic understanding of self-assembly phenomena in ultrathin organic films on metal, semiconductor, and insulator substrates; (2) modification of self-assembling monolayers (SAMs) by X-rays, electron irradiation, and plasma; (3) SAM-based lithography; (4) design of monomolecular films for different applications, ranging from the fabrication of sensors and catalytically active surfaces to molecular electronics; (5) X-ray and photoelectron microscopy characterization of ultrathin organic layers and polymer films; (6) adsorption of organic molecules on organic surfaces; (7) adsorption of metals and fabrication of ultrathin metallic films on monomolecular organic support; (8) spectroscopic characterization of liquids, and (9) spectroscopic characterization of biologically-relevant objects and macromolecules in their natural environment. The related activities take their course within several BMBF, DFG, and DAAD projects and include both experiments in the home laboratory and XPS, NEXAFS, HRXPS, XES, PSD, XPM, and XAM studies performed at different synchrotron radiation facilities, including BESSY II in Berlin, MAX-Lab in Lund (Sweden), ALS in Berkeley (USA), and NSRRC in Hsinchu (Taiwan). In the home laboratory, we have several specially designed, multi-technique UHV installations on our disposal. These machines consist of several analysis, preparation, and load-lock chambers connected by efficient sample transfer systems. They are equipped with a broad variety of complementary tools for surface analytics, such as, e.g., low-energy electron diffraction, thermal programmed desorption, X-ray and ultraviolet photoelectron spectroscopy, ion scattering spectroscopy, work function measurements, and photoelectron emission microscopy. In addition to the above scientific activities, the group conducts and participates in different industrial projects with national and international partners. The group is involved in a broad world-wide scientific cooperation with partners from Germany, Italy, Sweden, Netherlands, Switzerland, Poland, Russia, Israel, USA, Taiwan, and Japan. During last five years, we have published and submitted 67 manuscripts in reviewed, high-rating journals and presented 88 contributions at different national and international conferences.

Group: Surface science and analytics

Contact: Michael Zharnikov