Effect of α,α′-bipyridine on activity of the polyaniline uricase electrode

Abstract

An inactive polyaniline uricase electrode can be activated by α,α′-bipyridine and reused for determining the concentration of uric acid. The concentration of α,α′-bypridine hardly influences the response current. The reaction rate of the enzyme electrode with respect to uric acid increases with increasing applied potential and temperature. The response current of the enzyme electrode in the presence of α,α′-bipyridine increases linearly with increasing concentration of uric acid in the range below 0.6 mmol dm −3. The optimum pH of the inactive enzyme electrode in the presence of α,α′-bipyridine is 9.35, which is close to the value of 9.25 for the free uricase. The activation energy of the enzyme-catalysed reaction is 32.3 kJ mol −1 in buffer containing α,α′-bipyridine.