An electrode for uric acid has been prepared by using an iodide selective electrode with the uricase enzyme. The iodide selective electrode used was prepared from 10% TDMAI and PVC according to our previous study. The enzyme was immobilized on the iodide electrode by holding it at pH 7 phosphate buffer for 20 min at room temperature. The H2O2 formed from the reaction of uric acid was determined from the decrease of iodide concentration that was present in the reaction cell. The potential change was linear in the 2 × 10-5 to 2 × 10-4 M uric acid concentration (3 - 34 mg uric acid/100ml blood) range. Uric acid contents of some blood samples were determined with the new electrode and consistency was obtained with a colorimetric method. The effects of pH, iodide concentration, the amount of enzyme immobilized and the operating temperature were studied. No interference of ascorbic acid, glucose and urea was observed.
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