Optics-intrinsic double-circle phenomenon in protein adsorption visualized by confocal laser scanning microscopy

Investigating Protein Adsorption via Spectroscopic Ellipsometry

In this chapter, the basic concepts behind ellipsometry and spectroscopic ellipsometry are discussed along with some instrument details. Ellipsometry is an optical technique that measures changes in the reflectance and phase difference between the parallel (R_P) and perpendicular (R_S) components of a polarized light beam upon reflection from a surface. Aside from providing a simple, sensitive, and nondestructive way to analyze thin films, ellipsometry allows dynamic studies of film growth (thickness and optical constants) with a time resolution that is relevant to biomedical research. The present chapter intends to introduce ellipsometry as an emerging but highly promising technique, that is useful to elucidate the interactions of proteins with solid surfaces. In this regard, particular emphasis is placed on experimental details related to the development of biomedically relevant conjugated surfaces. Results from our group related to adsorption of proteins to nanostructured materials, as well as results published by other research groups, are discussed to illustrate the advantages and limitations of the technique.