Berlin 2012 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 8: Posters: Biopolymers and Biomaterials (with CPP)
BP 8.10: Poster
Montag, 26. März 2012, 17:30–19:30, Poster A
Influence of subsurface properties on proteins, bacteria and geckos: Is adhesion superficial? — •Peter Loskill1, Hendrik Hähl1, Jonathan Puthoff2, Kellar Autumn2, and Karin Jacobs1 — 1Saarland University, Experimental Physics, D-66041 Saarbrücken, Germany — 2Department of Biology, Lewis & Clark College, Portland, OR 97219, USA
Understanding and controlling the adhesion of biological objects to inorganic surfaces are important tasks that find application in various topics such as in the development of antimicrobial surfaces or artificial adhesives. To characterize biological adhesion, most studies describe a substrate solely by its surface properties. The composition of the material beneath the surface is frequently overlooked. That way, long-range van der Waals (vdW) interactions are disregarded. Previous studies revealed that microscopic biological objects such as proteins are affected by vdW interactions. We could show now that mesoscopic and even macroscopic objects are also influenced by differences in the microscopic interface potential. By using tailored silicon wafers with variable silicon dioxide layer thickness, we were able to tune the vdW part of the interface potential independently of the surface properties. On these substrates, we performed adhesion measurements with bacteria of the Staphylococcus genus and with a species of tropical gecko. The bacterial adhesion was explored via atomic force microscopy in the forces spectroscopy mode, using cantilevers on which living bacteria were immobilized. To characterize the gecko adhesion, we mimicked the typical gecko movement with a custom mechanical testing platform.