Optical Materials and Device Fabrication for Chemical Sensing on the Nanoscale

摘要

The program focus is to create new optical sensors based on bio- inspired concepts and use them for sensing applications of relevance to the United States Air Force, especially for applications in the micro- and nano- domains. This proposal seeks to unite the areas of optical chemo/bio-sensing (CB sensing) and nanoscience. As the advancement of chemical sensing systems progresses towards small length scales, sensitivity and performance are compromised because there are simply too few sensing active sites on the micro- and nano-patterned structures to permit detection of species. Accordingly, this proposal seeks to develop strategies to increase CB sensor response by replacing the linear, single photon response of present sensors with extremely nonlinear optical responses. To achieve this objective, a multi-prong approach that combines materials chemistry, engineering and optical science is presented in which the light emitting molecular centers of conventional optical chemosensors are substituted with a mesoscopic optical laser cavity of Distributed Feedback (DFB) structures and spherical cavity resonators exhibiting Whispering Gallery Modes (WGM). By tuning the frequency of the resonator to a specific property of the target biomolecule, the laser response can be interrupted upon recognition of the target at the surface of the resonator. In this way, a large change in nonlinear laser signal is easily detected upon target recognition.