Urate oxidase electrode based on dissolved oxygen probe for urine uric acid determination

A biosensor for the specific determination of uric acid in urine was develo ped using urate oxidase (EC 1.7.3.3) in combination with a dissolved oxygen probe. Urate oxidase was immobilized with gelatin by means of glutaraldehy de and fixed on a pretreated teflon membrane to serve as enzyme electrode. The electrode response was maximum when 50 mM glycine buffer was used at pH 9.2 and 35 degrees C. The enzyme electrode response depends linearly on ur ic acid concentration between 5-40 mu M with a response time of 5 min. The enzyme electrode is stable for more than 2 weeks and during this period ove r 35 assays were performed.