Fabrication of dissolved O₂ metric uric acid biosensor based on uricase bound to PVC membrane

Abstract

This study presents fabrication of dissolved O₂ (DO) metric uric acid biosensor based on uricase bound to PVC membrane

with 87% retention of initial activity of free enzyme. Enzyme membrane conjugate was mounted over sensing part of combined

electrode of DO meter (Aqualytic-OX53, Germany) to construct a uric acid biosensor, which showed optimum response within

10-12 s at pH 9.0 and 35^°C. A linear relationship was found between uric acid concentration (lower conc. range, 0.1-0.8 mg/dl;

higher conc. range, 1.0-10.0 mg/dl) and O₂ (mg/l) consumed. Biosensor showed mean uric acid level in serum in apparently

healthy males (6.1 mg/dl) and healthy females (4.9 mg/dl). Enzyme electrode showed only 32% decrease in initial activity after

100 reuse over 60 days when stored at 4^°C.