Phase-sentitive bloch surface wave biosensors

We report on the practical implementation of an angularly resolved ellipsometric optical sensing scheme based on Bloch surface waves sustained by tantala/titania/silica multilayers. The angular resolution is obtained by a focused illumination at fixed wavelength and detecting the angular reflectance spectrum by means of a CMOS array detector. The experimental results, obtained by using one tantala/titania/silica/multilayer defined structure, show the limit of detection below 6.5*10-7 RIU/Hz1/2. The physical characterization of the biosensors and their practical use with biological protocols is reported.