Fluorescent semiconductor nanocrystals or quantum dots have many properties that make them superior to traditional dyes as fluorescent markers. Quantum dots have higher extinction coefficients making them brighter than traditional dyes (up to 1000 times brighter than fluorescein); they do not photobleach; they are not toxic; and different sized quantum dots of the same semiconductor composition have the same excitation wavelengths but different emission maxima, allowing multiple quantum dot markers to be detected using a single excitation light source. The increased brightness and photostability of quantum dots will lead to increased sensitivity, making them ideal in high sensitivity applications such as pathogen and biowarfare/bioterrorists agent detection. In microfluidic systems based on fluorescent technologies, the weak strength of the fluorescent signal often limits the sensitivity of the devices. Therefore, Agave BioSystems proposes combining quantum dot and microfluidic technologies to generate a new class of ultra-small, highly efficient fluorescent-based microfluidic devices. To meet this goal, Agave BioSystems, in consultation with Dr. James Leary, of the University of Texas Medical Branch at Galveston, proposes to utilize water-soluble quantum dots to label biological components such as antibodies or other biologically important receptor molecules. Once these quantum dots are bioconjugated, they will be tested in a microfluidic flow cytometer developed by Agave BioSystems to demonstrate their capabilities for the detection and quantification of fluorescently labeled cells. Agave BioSystems has demonstrated the capability to develop and fabricate a micro flow cytometer chip that is self contained and disposable. In the Phase I, Agave BioSystems successfully completed the stated specific aims and clearly demonstrated proof of concept for the proposed technologies. In the Phase II, we will develop and construct a micro flow cytometer system specifically designed for use with quantum dot conjugated probes and then develop a number of practical, high utility assays. ? ? ?
