Dresden 2009 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 37: Biopolymers (joint session CPP/BP)

CPP 37.8: Talk

Thursday, March 26, 2009, 16:30–16:45, ZEU 114

Adsorption kinetics of proteins on tailored surfaces: An ellipsometry study — •Samuel Grandthyll, Hendrik Hähl, Hubert Mantz, and Karin Jacobs — Saarland University, Experimental Physics, D-66041 Saarbruecken, Germany

The adsorption of proteins onto solid surfaces is an everyday phenomenon. For a better understanding of the driving forces inducing the formation of the initial protein layer, we have studied the adsorption kinetics of three different proteins: Bovine serum albumin (BSA), α-amylase and lysozyme.

Our focus had been on the influence of the substrate, where lock-and-key mechanism between protein and surface were absent. It is already textbook knowledge that protein adsorption is influenced by short-range forces arising from the surface chemistry and Coulomb interaction due to unscreened charges. We could show that also long-range van der Waals forces present between the protein and the sample substrate are important. These interactions depend on the thickness of the oxide layer of a silicon wafer and thus are easily alterable [1].

Ellipsometry measurements show that the kinetics of BSA and α-amylase on native thin oxide layers does not follow a standard adsorption model, because the kinetics curve is separated by two kinks. By including conformational changes of the proteins into Monte Carlo simulations, the experimental results could be qualitatively reproduced [2].

[1] A. Quinn et al., EPL. 81, 56003, (2008)

[2] M. Bellion et al., J. Phys.: Condens. Mat. 20, 404226, (2008)