Optical monosaccharide detection using anionic fluorescent dyes and boronic acid-modified viologen quenchers

Glucose is the body's main source of energy and the regulation of physiological glucose levels is critical to human health. Glucose monitoring systems can provide patients and clinicians with real-time data and allow them to make the necessary interventions to maintain proper levels. Our lab has pursued a two-component approach to glucose sensing in which a boronic acid saccharide receptor is covalently attached to a viologen quencher molecule. In the absence of glucose, this boronic acid-modified viologen will quench, or turn off, the fluorescence of the dye. However, when glucose or other monosaccharides are added and bind to the boronic acid, the quenching ability of the viologen is diminished and fluorescence increases. Thus, the fluorescence of the dye can be correlated with glucose concentrations. Both the quenching and sugar sensing results are explained by an electrostatic interaction between dye and quencher.; We have pursued this two-component approach to glucose sensor design and explored the use of a variety of dye and quencher molecules in both solution studies and in immobilized form. The research reported herein involves the design, synthesis, characterization, and evaluation of different dye and quencher components for use in this two-component system. These compounds were assessed both in solution studies and immobilized sensor configurations.; The first chapter of the thesis provides background information on common glucose sensing strategies and offers the reader a primer on the essentials of related spectroscopy. The second and third chapters deal, respectively, with variations in the quencher and dye components in our system. The fourth and final chapter details our efforts to immobilize the sensing components in a hydrogel matrix for continuous glucose monitoring. The ultimate goal of this research was to prepare a continuous glucose sensing system for in vivo use.