REACTION-RATE MEASUREMENTS BY USE OF MEMBRANELESS FLOW-THROUGH BIOSENSORS

Three different approaches to performing reaction-rate measurements by using flow-through optical biosensors are proposed. This type of biosensor consists of a special flow-cell located in a conventional spectrophotometer, on the inner walls of which a biocatalyst is immobilized. Reaction-rate measurements can be made by coupling the biosensor on-line to different flow-injection (FI) manifolds: a normal FI system in which the flow is halted while the sample plug is in the flow-cell; another where the flow direction is changed iteratively; and an open-closed configuration. The performance of the three manifolds is critically studied and compared by using the same biosensor (immobilized beta-D-glucuronidase) for the determination of glucuronide derivatives.