DUAL-ENZYME FIBER OPTIC BIOSENSOR FOR PYRUVATE

In this study, the response characteristics for a dual-enzyme fiber-op tic biosensor for pyruvate are presented. An enzyme layer composed of lactate oxidase and lactate dehydrogenase (LDH) was fabricated at the tip of a sensing optrode. The biosensor is based on the luminescence d etection of consumed reduced nicotinamide adenine dinucleotide (NADH) and the measured fluorescence intensity is related to the bulk concent ration of pyruvate. Such a dual-enzyme optrode can not only retain the merits of fiber-optic biosensors, but can also take advantage of two enzyme-catalyzed reactions. The response sensitivity and detection lim it of the proposed dual-enzyme sensors are improved by at least 8 and 5 times, respectively, compared to those of single-enzyme systems.