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Molecular surface characterization using microprobes in light gradients


Research objectives and content
Laser trapping is emerging as a powerful and promising tool to improve our knowledges in the fields of nanotribology, biophysics and material testing. With 'optical tweezers' we can expose single bonds under load . and test material properties of molecular structures in liquids over a force range centered in piconewtons. For instance, it is possible to study in a very direct way the processes of molecular adhesion between soft interfaces and measure in vivo the forces acting at molecular level in biological systems.
Project objectives
1) Development of advanced and flexible optical tweezer systems, a) to obtain high performances in the fields of forces sensoring, force mapping and material testing, b) to test different trapping geometries and configurations. 2) Development of a dedicated software to automatically control, programmeand monitor all the relevant parameters correlated to the trapping system, such laser power, laser focus, fine movements of the trap in 3D-space, sub-nanometer probe positioning-system, image acquisition system. 3) Improvement of an innovative method of surface characterization, based on the measurement of the friction between microprobes held by the laser trap (for example micrometer sized polystiren beads functionalized with chosen molecules) and the sample (cell surface, functionalized thin films, surfaces with special coatings). 4) Applications: mapping of cell receptors to understand the functional significance of tumour-associated cell surface alterations; study of chemical/mechanical properties of artificial membranes and liposomes, characterization of surfaces with special coatings.
Training content (objective, benefit and expected impact)
From my Ph.D. research project I expect to acquire all the scientific training and the necessary technological knowledges to be competitive in the emerging fields of surface characterization and mapping, in vivo monitoring of biological processes at molecular level and nanotechnology. All these fields can be expected to be of increasing importance in the future, both at the level of foundamental research and at the level of applied high technology.
Links with industry / industrial relevance (22)
SL Microtest GmbH (Jena - Germany); Merck KGaA (Darmstadt - Germany); Boehringer Mannheim GmbH (Germany)

Funding Scheme

RGI - Research grants (individual fellowships)


Universität Regensburg
31,Universitätstrasse 31
93040 Regensburg