COMPARISON OF DIFFERENT BIOSENSOR SYSTEMS SUITABLE FOR BIOPROCESS MONITORING

To achieve effective bioprocess monitoring, sensing systems are requir ed which are suitable for an on-line determination of substrates, inhi bitors, nutrients or products. Such devices may utilise biochemical pr inciples, i.e. the specific interaction of biochemical receptors with their surroundings. They can be constructed either as in situ sensors or as flow-through sensors connected to the process via sampling devic es. Hence, characteristic features of an in situ glucose electrode are described, e.g. analytical range, sensitivity and stability. The sens or was based on mediated electron transfer from the enzyme glucose oxi dase to the graphite electrode, the mediators being tetrathiafulvalene (TTF) or dimethylferrocene (DMF). Additionally, various flow injectio n analysis (FIA) systems based on oxidases, which were immobilised eit her on controlled pore glass or in a membrane, were characterised with respect to analytical ranges and sensitivities and applied to glucose , lactate and glutamate determinations in off-line samples taken from an animal cell cultivation.