Adsorption and Morphology Analysis of Bovine Serum Albumin on a Micropillar-Enhanced Quartz Crystal Microbalance.

The adsorption of bovine serum albumin (BSA), a widely used blood plasma protein, onto poly(methyl methacrylate) (PMMA) surface is a fundamental phenomenon attracting increasing interests in molecular biology, cell culture, immunology, diagnostics, and vaccinology. The nanostructured PMMA surfaces have shown a considerable effect on the BSA adsorption process. However, the effect of microstructures (e.g., micropillars) on BSA adsorption has seldom been studied. This research reports on the development of an acoustic resonance based method to explore the adsorption of BSA proteins on PMMA micropillars in terms of surface coverage, apparent binding constants, and pH-induced morphology variation. A theoretical model is developed to understand the frequency changes of QCM induced by BSA adsorption by taking into consideration the effects of the hydrodynamic force and an equivalent BSA/liquid layer formed on the micropillar surface. In addition, it was found that the resonance of micropillars with a quartz crystal microbalance (QCM) substrate significantly influenced BSA adsorption on micropillar surfaces.