Colorimetric Sensors for Chemical and Biological Warfare Agents

1. Abstract. The Mirkin group at Nortwestern University has developed methods for exquisitely sensitive analyte detection that rely upon forming hybridized arrays of nucleic acid-derivatized gold nanoparticles. These methods lend themselves immediately to colorimetric detection and dipstick-style applications. The hybridized nanoparticles are (quite literally) ‘blue,’ the separated nanoparticles are ‘red.’ Dr. Mirkin is working closely with a company, Nanosphere Inc., on the commercial applications of these technologies. In parallel, the Ellington group at the University of Texas at Austin has developed methods for transducing analyte-binding to nucleic acid receptors into conformational or bond changes that can alter hybridization. By combining these technologies it should be possible to produce generalized, sensitive, and simple detection methods for the detection of a variety of analytes relevant to biodefense. As a proof-of-principle in Phase I, we will generate dipsticks that will change color from blue to red at low (nanomolar) concentrations of the biothreat agent ricin. In Phase II we will generalize these methods to a much wider array of chemical and biological threat agents, and will continue to partner with Nanosphere Inc. on the commercialization of these technologies.