SUBMICRON FIBER OPTIC CHEMICAL SENSORS WITH MILLISECOND RESPONSE TIMES

IN APPLICATIONS AS DIVERSE AS SEMICONDUCTOR ELECTRONICS, IN WHICH MICROFABRICATION TECHNOLOGY REQUIRES CHEMICAL PROCESSING OF SUB-MICROMETER SIZED FEATURES, AND BIOTECHNOLOGY, WHERE CHEMICAL MANIPULATIONS ARE ROUTINELY PERFORMED ON SINGLE CELLS, RELIABLE MICROMINIATURIZED CHEMICAL SENSORS ARE NEEDED. THE OBJECTIVE OF THIS RESEARCH PROJECT IS TO DEVELOP SUCH SENSORS USING TWO RECENT THEORETICAL AND TECHNOLOGICAL BREAKTHROUGHS: A MICROFABRICATION TECHNIQUE THAT ALLOWS THE CONSTRUCTION OF OPTICAL FIBERBASED LIGHT SOURCES AND SENSORS WITH SIZES AS SMALL AS 40 NM, AND THE DEMONSTRATION OF NEAR-FIELD OPTICS IN MICROSCOPY AND CHEMICAL IMAGING. THESE SENSORS ARE SO SMALL THAT, IN BIOLOGICAL APPLICATIONS, THEY CAN BE USED TO MEASURE CHEMICAL CONCENTRATIONS IN SINGLE CELLS WITHOUT DAMAGE. RESEARCHERS WILL FABRICATE AND TEST A WORKING PH SENSOR WITH MILLISECOND RESPONSE TIME AND EXCELLENT SENSITIVITY (0.01 PH), REQUIRING ONLY ATTO-LITERS (10-(18)LITERS) OF SAMPLE. THEY WILL ALSO FABRICATE AND DEMONSTRATE A SIMILAR SENSOR FOR OXYGEN. THESE SENSORS WILL BE MUCH LESS INVASIVE, AND MUCH MORE CHEMICALLY SELECTIVE, THAN EXISTING SENSORS, AND WILL INCREASE BOTH THE SPEED AND RELIABILITY WITH WHICH MICROCHEMICAL MEASUREMENTS CAN BE PERFORMED.