This research is on biomedical pCO2 sensors based on advanced fiber optic technology. Research will focus on the development of a pCO2 analysis system that performs real-time, in-vivo, continuous monitoring of pCO2 in physiological concentration ranges. Specifically, efforts will be directed toward the optimization of the choice of polymer/dye matrices to achieve desired response time, reliability, stability, selectivity, and aging. A goal is to preserve small sensor size by covalently binding the sensor chemistry directly to the fiber sensor tip. A successful sensor should have significant medical applications.