Microring Resonator Biosensors
Microring resonators provide high sensitive label-free optical biosensor platforms. The light coupled into the resonator via a waveguide is confined within the microring cavity due to total internal reflections and high-Q resonant modes (Q~12000) are formed. The positions of these modes depend on the effective index of the resonant structure and thus get shifted when there is a molecular interaction on the surface. This shift can be determined with high precision using our method of detection. We have accomplished to demonstrate biosensing application of the microring resonators by investigating a well studied binding event (Avidin-Biotin complex). The high sensitivities (1.8×10-5 refractive index units) obtained with this method are comparable to commercially available surface plasmon resonance devices.
The detection methods that are currently available deliver high sensitivity and specificity; however they fail to provide a clear path to compact optical packaging that will lead to portable devices for field use. Towards this goal, and with the efforts of our interdisciplinary research team and industrial collaborators, we are currently modifying our table-top, fiber-coupled system to develop a cost- efficient, compact integrated biosensor platform.