Total internal reflection ellipsometry in the investigation of phenomena at surfaces and interfaces for biosensing

Ellipsometry, particularly spectroscopic ellipsometry, is a very sensitive, nondestructive experimental technique of thin film characterisation. The recently proposed method of Total internal reflection ellipsometry (TIRE) combines the advantages of spectroscopic ellipsometry and the Kretschmann type SPR geometry of total internal reflection. The modeling reveals detection limit of changes in the bulk refractive index, Δn_b= 1.5×10^-6 which represents the instrumental potential for detecting an analyte at several pmol/liter in a solution. These results were proven by experimental studies on monitoring changes in adsorbed layers (at the metal / dielectric interface) caused by specific binding of biomolecules from the surrounding solution.