Previous studies of protein adsorption on silicon have been restricted by the choice of a simple structure or large surface for protein to adsorb on. The aim of this project was to develop an optical model for more complex nanostructures in form of trenches etched in silicon and then examine if a protein would adsorb to the surface. The method used was infrared ellipsometry. The experimental values from measurements on the sample were used to develop an optical model that represent the nanostructure. A three-layered biaxial model proved to be accurate. One sample was then exposed to the protein albumin and then measured upon again. The results before and after protein adsorption were compared and a small optical signature was found were it could be expected for this specific protein. This shows that it is possible to detect adsorption in a complex nanostructure and to develop an accurate optical model for said structure.

<p>Previous studies of protein adsorption on silicon have been restricted by the choice of a simple structure or large surface for protein to adsorb on. The aim of this project was to develop an optical model for more complex nanostructures in form of trenches etched in silicon and then examine if a protein would adsorb to the surface. The method used was infrared ellipsometry. The experimental values from measurements on the sample were used to develop an optical model that represent the nanostructure. A three-layered biaxial model proved to be accurate. One sample was then exposed to the protein albumin and then measured upon again. The results before and after protein adsorption were compared and a small optical signature was found were it could be expected for this specific protein. This shows that it is possible to detect adsorption in a complex nanostructure and to develop an accurate optical model for said structure.</p>