Improving the sensitivity of optical biosensors by means of Bloch surface waves

One factor limiting the performance of Surface Plasmon Resonance (SPR) biosensors is the width of the resonance that basically originates from metal absorption. In contrast, comparable sensing schemes based upon the concept of Bloch surface waves (BSW) have been proposed. As such sensors are prepared from dielectric materials only, losses as well as the resonance width decrease significantly in comparison to SPR. By preparing BSW stacks that feature a similar resonance position as Gold based SPR sensors, both approaches are compared directly using one detection system only. We obtain an increased performance of BSW although utilizing an optical system optimized for SPR analysis.