Amperometric biosensor for uric acid based on uricase-immobilized silk fibroin membrane

Abstract An amperometric urate sensor based on a uricase-immobilized silk fibroin membrane and an oxygen electrode in flow injection analysis are described in the present paper. The biosensor shows that recoveries of uric acid in human serum and urine are in the range of 94.2–102.6% and 92.5–97.9%, respectively. The relative standard deviations (RSDs) for repeatedly monitoring standard urate solution, human serum and urine are 2.37, 3.72 and 2.95%, respectively, based on 100 measurements. The urate sensor based on the uricase-immobilized membrane is capable of detecting 60–70 human serum samples per hour. Moreover, a piece of uricase-immobilized fibroin membrane used at the sensor could not only be stored for over 2 years, but also repeatedly monitored more than 1000 times for biosamples such as human serum or urine.