Mutharasan The goal of this research is to develop Antibody Sensitized Tapered Fiber Sensors arrays and Oligonucleotide Signatured Fiber Sensors for rapid direct detection and quantification of bioterrorism agents and their confirming DNA signatures using optical means with high specificity and sensitivity, and very low false positives. The proposed sensors will use evanescent absorption, scatter and fluorescence in continuous biconical tapered fibers for detection and quantification. The investigators will examine one- and multi- photon evanescent absorption, scatter and fluorescence for detection. The proposed sensors will not only measure the presence of bioterrorism agent(s) at very high sensitivity, but also establish their viability. The use of multiple strategies: evanescent absorption, scatter and fluorescence in single and multi-photon mode with the aid of surface immobilized monoclonal antibodies and unique DNA sequences specific to the target organism offers a comprehensive approach for detection.
The broader impacts of this research are several-fold. The ability to detect and identify the presence or absence of pathogens or bioterrorism agents is essential for fighting terrorism. In addition, pin pointing the nature of the pathogen, especially its viability and virulence is paramount. If these can be accomplished expeditiously at the resolution of a single bacterium, the benefits to the society could be enormous. In addition, the sensors developed under this research can also be used for metabolic imaging of tissue in vivo. By positioning the tapers external to the tissue, the penetration of the 2-photon fluorescence excitation will enable the metabolic activity information from depths of several centimeters to be determined optically. A sequence of these tapers over the breast (as an example) can identify malignant tumors several centimeters beneath the surface.
