Low Cost Optrodes for Chemical Sensor Development of Tethered PET-Fluorophores

Besides temperature, pH measurement is one of the most common controls used in the processing of aqueous media within various industries. One example is in chemical processing where titration is often used to drive the pH to a certain level, in order to initiate, maintain, optimize, or terminate reactions. Another instance involves the monitoring of cell growth bioreactors, where microbial and especially mammalian cell cultures demand that the pH be maintained within a very narrow range. However, existing pH-sensing systems have a number of limitations: hazards to sample volumes, generation of unreliable data, a small sensitivity range, photo bleaching, and hysteresis. The Phase I project will synthesize a series of fluorophores in which the pH sensitivity is not contained within the fluorophore itself (as with conventional fluorescent dyes) but rather in a receptor that reports changes in pH by means of Photo-Induced Electron Transfer (PET). Phase II will design and develop a pH-sensitive optrode that incorporates the PET fluorophore ensemble of Phase I. Commercial Applications and other Benefits as described by the awardee: Given the increasing energy and environmental costs, the new pH sensing technology should enable manufacturers to improve efficiency and thereby keep the expense of goods in a competitive range.