A FIBER OPTIC BIOSENSOR BASED ON FLUOROMETRIC DETECTION USING CONFINED MACROMOLECULAR NICOTINAMIDE ADENINE-DINUCLEOTIDE DERIVATIVES

A novel type of fiber optic biosensor is presented. A miniaturized fiber optic fluorometer is combined with a solid membrane reactor that retains enzymes (dehydrogenases) as well as macromolecular adenine dinucleotide coenzyme derivatives, e.g. PEG (MW 20 000)-N6-(2-aminoethyl)-NAD(H), in the direct vicinity of the sensor tip. The whole system is operated according to the principles of flow-injection analysis (FIA). Three different enzymes (l-lactic dehydrogenase, alcohol dehydrogenase, and glutamic-pyruvic transaminase) were used to demonstrate the feasibility of the novel optical biosensor. Assays for lactate, pyruvate and ethanol were established. In the system described high signal sensitivity and enzyme stability were observed. © 1990.