Interaction forces between BSA layers adsorbed on silica surfaces measured with an atomic force microscope
2004 (English)In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 108, no 17, 5365-5371 p.Article in journal (Refereed) Published
The interaction forces between bovine serum albumin (BSA) layers adsorbed on silica surfaces have been measured using an atomic force microscope (AFM) in Conjunction with the colloid probe technique. Measurements of force-distance curves were made at different pH values and electrolyte concentrations (NaCl and CaCl2). The interaction at long range is dominated by electrical double-layer forces, while at short surface separations an additional repulsion due to the compression of the adsorbed protein layers appears. However, prior to this steric interaction, when the pH is above the isoelectric point of the protein and at high salt concentration, a non-DLVO repulsive interaction is observed. This behavior is explained if the presence of hydration forces in the system is assumed. Theoretical predictions including a hydration term in the DLVO theory fit the experimental results satisfactorily. The results presented in this article provide a direct confirmation that the AFM colloid probe technique can provide a useful way of directly quantifying the interaction of biological macromolecules.
Place, publisher, year, edition, pages
2004. Vol. 108, no 17, 5365-5371 p.
aqueous-electrolyte solutions, hydration forces, colloidal stability, mica surfaces, long-range, solid-surfaces, protein layers, particles, adsorption, aggregation
Other Chemistry Topics
IdentifiersURN: urn:nbn:se:kth:diva-23355DOI: 10.1021/jp0374197ISI: 000220997300035ScopusID: 2-s2.0-2442587880OAI: oai:DiVA.org:kth-23355DiVA: diva2:342053
QC 201005252010-08-102010-08-102011-11-01Bibliographically approved