The increasing demand for early detection of diseases drives the efforts to develop more and more sensitive techniques to detect biomarkers in extremely low concentrations. Electromagnetic modes at the surface of one dimensional photonic crystals, usually called Bloch surface waves, were demonstrated to enhance the resolution and constitute an attractive alternative to surface plasmon polariton optical biosensors. We report on the development of Bloch surface wave biochips operating in both label-free and fluorescence modes and demonstrate their use in ovalbumin recognition assays.
Surface plasmon resonance imaging is an optical method that allows the real time detection of small changes in the physical properties of a dielectric medium near a metallic surface. Using proper surface functionalization and structuration, this technique can be applied to the realization of optical biochips where multiple unlabeled interactions can be monitored. More precisely, thanks to the use of an adequate optical set-up built around a gold surface realized by self assembled monolayers or electrocopolymerization, we studied DNA:DNA interactions with potential application to genetic diagnostic and DNA:protein interactions to demonstrate the ability of the system to determine simultaneously different affinity constants.