X-ray Surface Scattering for
the Structural Analysis of Adsorbed Proteins at Hydrated Interfaces
Carrie A. Pavloski*, Syed Lateef*, Mark Schlossman°, and Luke Hanley*
*Department of Chemistry
°Department of Physics
University of Illinois at
Chicago
Chicago, IL 60607-7061
Abstract
Protein adsorption onto solid surfaces is a significant process in a wide variety of applications including biomaterials, tissue engineering, biosensors, immunoassays and protein arrays. Surface properties are altered by synthetic and naturally occurring molecular adsorbates when a biomaterial is brought into contact with a biological fluid. We are interested in determining the structural conformation of adsorbed proteins at this aqueous-solid interface. We examine the surface adsorption of bovine serum albumin (BSA), the most abundant protein in blood. We bromine label BSA to allow probes of its adsorbed conformation on an amine-functionalized monolayer on a silicon wafer. We use x-ray photoelectron spectroscopy and atomic force microscopy to study the chemistry and structure of the dry surface. We then apply x-ray reflectivity and x-ray standing wave fluorescence to probe the conformation of adsorbed BSA at the hydrated interface.