Microring resonators: the promise of a powerful biochemical sensor platform

Microring resonators constitute ideal microspots where the target reaction are spatially confined and exhibit high signal density. These devices have very high quality factors, Q up to 10/sup 8/ which translates to enhanced sensitivity and signal-to-noise ratio. The combination of high Q and small geometry leads to significant power buildup within the microcavity and can allow the accurate detection of very few molecular events on the ring surface. We have designed and fabricated devices with different geometries and optimized operational wavelength ranges. In addition to high volume microfabrication, Hydex/sup /spl trade// allots us to functionalize the ring using established immobilization protocols for antibodies, nucleic acids, receptors and artificial sensing layers. Preliminary testing used the well documented and versatile biotin-avidin complex to immobilize an antibody biofilm. With Hydex/sup /spl trade// we can design highly-sensitive, readily portable label-free and reagent-free assays.