Biosensing and Biofunctionalisation

The research activities of the Länge group include surface modification of biosensors and other bioanalytical devices, innovative biofunctional coatings, and development of bioanalytical systems for life science applications. The R&D activities are divided in three main parts:

Biomarker quantification

The degree of selectivity and specificity of bioanalytical systems, such as biosensors, is determined by the biofunctionalization of the device surface. Surface functionalization must guarantee the binding of analyte molecules, but it must also prevent non-specific binding to avoid false-positive signals. Besides, the biofunctionalization procedure has to be chosen in accordance to the chemical environment provided by device and housing material as well as to the detection principle. Current applications include the detection of cancer markers and the investigation of markers relevant for sports medicine with biosensors.

Biomolecular interaction analysis (BIA)

This topic deals with the quantification of protein-protein or protein-ligand interactions. It includes time-resolved monitoring of the binding of one binding partner to the corresponding binding partner, which is immobilized on the transducer surface of a label-free biosensor. Kinetic and thermodynamic constants of this surface binding reaction are calculated from the biosensor signal curves. BIA is used, for instance, for the characterization of molecular processes which are involved in cancer development.

Monitoring conditioning film formation 

The formation of conditioning films typically precedes the formation of biofilms, i.e., interfacial aggregates of microorganisms. Though biofilms are a common phenomenon, they are not yet fully controllable. They may be beneficial, e.g., in biotechnological processes, but they may also lead to biofouling. Conditioning film monitoring requires sensors which can be coated with any material without interfering with the signal transduction mechanism. This is offered, for instance, by mass-sensitive sensors, as used in our group. Current applications include the monitoring of proteinaceous conditioning films on implant surfaces.