Center for Functional Nanomaterials Seminar

The autonomous detection of pathogens in the environment remains an unmet challenge. The Los Alamos Optical Biosensor Team is developing a toolbox of dual-use technologies that can be used to address this challenge as well as medical diagnostics. The tools under development include robust ligands, reporters and sensing surfaces as well as signal transduction approaches that are reagent free and yet highly specific. Current reagent free approaches (e.g., SAW, SPR, microcantilever) all sense anything that interacts with the surface. What is needed is a transduction approach where a specific molecular recognition event is the only thing that triggers a signal. The heart of our approach is to use molecular recognition to trigger signal transduction at the surface of a single mode planar optical waveguide. We utilize the exponential decay of the evanescent optical field and the modulation of fluorescence from a semiconductor quantum dot optical reporter that is moving in and out of this evanescent field as the signal. We utilize chaperonin proteins conjugated to quantum dots as the optical reporters, as these nanobio materials can be engineered to present recognition ligands that specifically target the analytes of interest. Progress on the development of this new transduction approach as well as robust, regenerable sensing films and stable ligands that go beyond antibodies will be presented. The adaptation of these tools to the detection of multiple disease markers for influenza, breast cancer and tuberculosis will also be discussed.