Effect of alpha,alpha'-bipyridine on activity of the polyaniline uricase electrode

An inactive polyaniline uricase electrode can be actived by alpha,alpha'-bipyridine and reused for determining the concentration of uric acid. The concentration of alpha,alpha'-bipyridine 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 alpha,alpha'-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 alpha,alpha'-bipyridine is 9.35, which is dose 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 alpha,alpha'-bipyridine.