Adsorption and Morphology Analysis of Bovine Serum\nAlbumin on a Micropillar-Enhanced Quartz Crystal Microbalance

The adsorption of bovine serum albumin (BSA), a widely\nused blood\nplasma protein, onto poly(methyl methacrylate) (PMMA) surface is a\nfundamental phenomenon attracting increasing interests in molecular\nbiology, cell culture, immunology, diagnostics, and vaccinology. The\nnanostructured PMMA surfaces have shown a considerable effect on the\nBSA adsorption process. However, the effect of microstructures (e.g.,\nmicropillars) on BSA adsorption has seldom been studied. This research\nreports on the development of an acoustic resonance based method to\nexplore the adsorption of BSA proteins on PMMA micropillars in terms\nof surface coverage, apparent binding constants, and pH-induced morphology\nvariation. A theoretical model is developed to understand the frequency\nchanges of QCM induced by BSA adsorption by taking into consideration\nthe effects of the hydrodynamic force and an equivalent BSA/liquid\nlayer formed on the micropillar surface. In addition, it was found\nthat the resonance of micropillars with a quartz crystal microbalance\n(QCM) substrate significantly influenced BSA adsorption on micropillar\nsurfaces.