Bioelectrochemical responses of the polyaniline uricase electrode

Abstract

The catalytic activity of the polyaniline uricase electrode is very sensitive to uric acid. At a very low concentration of the substrate, such as 1. 2 × 10 −6 mol dm −3, uric acid can be determined reliably by using a polyaniline uricase electrode. The response current increases linearly with increasing concentration of uric acid in the region of 1.2 × 10 −6 to 1.2 × 10 −3 mol dm −3. The reaction rate of the enzyme electrode is affected quite significantly by potential: the response time of the enzyme electrode at 0.35 V (vs. SCE) is about 40 s. The effect of the solution pH on the electrode reaction is rather complicated, the reaction rate increasing with rising temperature. The activation energy of the enzyme-catalyzed reaction is 29.9 kJ/mol.