Improved Optical Sensor for Monitoring Dissolved Oxygen

An optical sensor for measuring the partial pressure of dissolved oxygen in water is based on the effect of oxygen quenching on the fluorescence lifetime of an optically excited ruthenium complex immobilized in a recently developed polymer. In the operation of this sensor, the fluorescence lifetime and thus the degree of quenching and partial pressure of oxygen are measured by a phase-sensitive detection method described below. This sensor is a prototype of improved oxygen-concentration transducers, which are needed for monitoring critical oxygen concentrations in bioreactors and chemical plants.