Submicron Chemical Sensor for Intracellular Application

We will develop a new class of submicroscopic chemical sensors for use in the investigation ofcellular physiology. These sensors, which can have characteristic dimensions much smaller than lmicromole, have the potential for monitoring ionic concentrations, enzyme levels, drug concentrations,and a wide variety of other intracellular chemical properties, with relative ease to the researcher. In theproposed approach, chemically sensitive indicators would be immobilized by photopolymerization at thetip of finely tapered optical fibers similar to those used in Near-field Scanning Optical Microscopy(NSOM). The technique could thus combine the ultrafine resolution of NSOM with the sensitivity andspecificity of active fiber optic chemical sensors. These sensors offer significant advantages, includingfaster response time and minimization of cellular damage, when compared with existing (electrochemical)intracellular sensors. During Phase I of the project, POC will demonstrate the practicality of thistechnique by fabricating and testing sensors capable of measuring intracellular concentrations ofmetabolites, ions, or other chemical species of biological interest. Phase II will see expansion into themeasurement of other analytes, including biochemical substances such as enzymes and immunochemica-ls, as well as the development of a portable system capable of serving as the basis for a line ofcommercial intracellular sensing products.