The measurement of dissolved oxygen (D 0) consumption is fundamental in determining the reaction rate in bioreactors and requires a probe designed specifically for the bioreactor environment. Membrane covered D 0 probes suffer from slow response time, lack of self cleaning, and a susceptibility to stirring or agitation rate. It is proposed to build and test a new type of membraneless D 0 electrode which is designed specifically for the bioreactor environment. This new D 0 electrode will rely upon hydrodynamic modulation to maintain a region of laminar flow across its surface which is independent of bulk convective processes and will use three electrode voltametry to selectively reduce oxygen. Hydrodynamic modulation permits both self-cleaning and discrimination between adsorbed and dissolved electroactive species. Three electrode voltametry permits selective determination of oxygen in the presence of other electroactive species.The potential applications as described by the company: The commercial result of Phase I of this program will be a prototype design of a commercial D 0 Probe with a digital controller and meter designed and optimized specifically for bioreactors. The D 0 measurement system will feature real time D 0 measurement, self cleaning, steam sterilizability, and selectivity for oxygen, which are features not found with currently commercially available D 0 electrodes.
