We are working on developing an integrated on-chip biosensor for the detection of enzymes and bacteria using cavity-enhanced absorption spectroscopy. Present day methods of sensing bacteria rely on microbiological assays, which require day-long or more incubation periods, or PCRs, which are expensive. On-chip biosensors would enable low-cost detection of pathogens on much smaller timescales.
Light enhancement in optical microcavities is integrated with a microfluidic platform to produce optofluidic devices with increased the interaction of the cavity's evanescent field with the fluidic environment. The change in the transmission spectrum of the ring resonators, based on the change of absorption and not on the index of refraction, is used to quantify the concentration of biological materials within the channels.