Intracellular Detection of Small Molecules in Live Cells

ABSTRACT: The goal of this Phase I STTR project is to investigate the application of a new class of metallic nanoparticles exhibiting a star-shaped geometry (nanostars) for use as in vivo probes of chemical and biological warfare agents. In contrast to their more commonplace spherical cousins, particles with this novel geometry have recently gained interest due to their ability to focus and enhance electric fields around the star surface features. Field enhancement has been estimated to be as large as 10,000 times greater than that observed for spherical gold particles. In fact, single nanostar Raman signals can exceed those obtained from the brightest molecular fluors, even when imaged using common fluorescence instrumentation. Phase I work will take advantage of our previous experiences in fabricating these star-shaped nanoparticles by modifying their surfaces with specific chemistries that are tuned for agent concentration and binding at these enhanced electric field sites on the nanostars. In addition, control over the nanostar morphology will also be investigated for optimizing agent detection via spectroscopic detection systems. The outcome of these efforts will be to identify the optimum materials for development of a broad-based biosensor platform during Phase II. BENEFIT: The anticipated benefits of the research and development efforts outlined in this proposal will be the design, fabrication and testing of gold nanostar probes for intracellular chem/bio detection that presents significant advantages over existing methods by providing a biomolecular switch for detecting target agents in biological samples for real-time detection capabilities in complex environments.