The objective of this proposal is to develop a robust and inexpensive steam- sterilizable glucose sensor for the bioprocessing industry. This will be achieved by bonding Molecular System's patented glucose-sensing dye, polyboronate red, to the external surface of the core of a fiber optic probe. Polyboronate red will be bonded directly to the probe through linkage groups on the surface, or incorporated in a porous support polymer which will be coated on the fiber. Bonding techniques will be evaluated with a Polestar Technologies, Inc. MultiOptrode Monitor in terms of its sensitivity to glucose, rate of response, repeatability, and resistance to heat sterilization. PROPOSED COMMERCIAL APPLICATIONS: This Phase I program addressees the construction of a robust and inexpensive steam-sterilizable fiber-optic glucose sensor for direct in situ monitoring of the glucose levels in a bioprocessing fluid. Current methods of measuring glucose, such as with sensors based on glucose oxidase, cannot be sterilized by steam, while measurement by HPLC is expensive, slow, and requires tapping the reactor. These weaknesses are to be avoided by utilizing our patented glucose-sensing dye molecules, which withstand steam sterilization, in conjunction with an optical fiber. The project involves fixing the sensing dye to the surface of an optical fiber, and evaluating the performance in terms of sensitivity to glucose, reversibility, and reliability. The dye, which operates in the visible, lends itself to reasonably-priced instrumentation based on LEDs and standard optical fibers. The information obtained in the Phase I project will be utilized in a Phase II proposal to design a robust industrial sensor to fit in a standard 12 mm port.