Title

Materials and Strategies in Optical Chemical Sensing

Date of Award

2008

Document Type

Dissertation

Degree Name

Doctor of Philosophy (Ph.D.)

Department

Photochemical Sciences

First Advisor

Pavel Anzenbacher, Jr.

Second Advisor

Felix Castellanos, Ph.D. (Committee Member)

Third Advisor

Deanne Snavely, Ph.D. (Committee Member)

Fourth Advisor

John Laird, Ph.D. (Committee Member)

Abstract

The detection of chemical species that play an important role in biological systems, industrial processes or that are environmental pollutants demands the development of highly sensitive and selective chemical sensors capable of operating in various media, particularly in water. Reliable sensing in water is a difficult problem, thus analytical tests and sensor devices for detection in aqueous media remain rare. The present work describes the rational design and formulation of materials for the optical chemical sensing of anions and metal ions in aqueous solution. These materials consist of optical chemosensors embedded in hydrophilic poly(ether)urethanes, which mimic the synergy between proteins and cofactors in enzymes. The resulting materials are arrayed and used in tandem for the detection of single analyte and multianalyte samples, such as toothpaste, human blood serum and enhanced soft drinks. This work also aims to demonstrate that the discriminatory power of sensor arrays might be improved by the use of selective, yet cross-reactive sensing elements. The balance between the selectivity and the cross-reactivity allows for a significant reduction in the number of elements in the sensor array, thereby simplifying the pattern recognition protocols, training sets, and calibrations while maintaining the high overall reliability of the sensing process.