Evident Technologies proposes to optimize the design and application of quantum dots for biological labeling. To enable new dynamic, cellular biology research, we will demonstrate the advantages of the broad excitation spectra, including: narrow emission spectra, precise-tunable emission peaks, long fluorescence lifetimes, and negligible photobleaching properties of quantum dots. We will develop the design of organic coatings, bioconjugation schemes, targeting strategies, and unique instrumentation that take advantage of multiple quantum tags for cellular signaling characterization. We will also demonstrate that fluorescence lifetime can be used to observe molecules and organelles in live cells without interference from autofluorescence background. The benefits of the proposed research are significant. Experiments in cellular signaling are currently performed predominantly in in-vitro environments. The ultimate challenge is to image cellular substructures, determine the relationships and dynamics of vesicles and organelles, describe existing conformational dynamics and biomolecular interactions, and localization of all of the above in-vivo with single molecule sensitivity and nanometer-accuracy. This will allow the freedom to explore the answers to new questions by studying enzymes and multi-component molecular machines in their natural environment, with the signaling and regulation circuitry all wired-up
