POTENTIAL APPLICATIONS OF LIFETIME-BASED, PHASE-MODULATION FLUOROMETRY IN BIOPROCESS AND CLINICAL MONITORING

The measurement of analyte concentration is a critical part of success ful bioreactor and clinical monitoring. Although strategies exist for measuring the majority of relevant analytes, industrial on-line biorea ctor control is carried out primarily by measurement and control of pH , pO(2) and, in some cases, cell density. This is because the availabl e technology cannot be easily and inexpensively adapted to (a) measure the analyte in an aseptic manner and/or allow for remote sensing, and (b) measure in real time so that on-line control is possible. Similar issues need to be addressed for biosensors for clinical applications. A rapidly emerging technology that has the potential of meeting these challenges is lifetime-based phase-modulation fluorimetry, an optical technique that uses the measurement of fluorescence lifetime rather t han intensity for determining the concentration of an analyte.