AMPEROMETRIC BIOSENSOR FOR URIC-ACID BASED ON URICASE-IMMOBILIZED SILK FIBROIN MEMBRANE

An amperometric urate sensor based on a uricase-immobilized silk fibro in membrane and an oxygen electrode in flow injection analysis are des cribed in the present paper. The biosensor shows that recoveries of ur ic acid in human serum and urine are in the range of 94.2-102.6% and 9 2.5-97.9%, respectively. The relative standard deviations (RSDs) for r epeatedly monitoring standard urate solution, human serum and urine ar e 2.37, 3.72 and 2.95%, respectively, based on 100 measurements. The u rate sensor based on the uricase-immobilized membrane is capable of de tecting 60-70 human serum samples per hour. Moreover, a piece of urica se-immobilized fibroin membrane used at the sensor could not only be s tored for over 2 years, but also repeatedly monitored more than 1000 t imes for biosamples such as human serum or urine. (C) 1998 Elsevier Sc ience B.V. All rights reserved.