Enzyme immobilization on Ag nanoparticles/polyaniline nanocomposites.

Abstract

The performance of the modified electrodes toward urea hydrolysis was investigated via amperometric measurements, revealing a fast increase in cathodic current with a well-defined peak upon addition of urea to the electrolytic solution. The cathodic currents for the ITO/PAni/PVA–AgNP/urease electrodes were significantly higher than for the ITO/PAni/urease electrodes. The friendly environment provided by the ITO/PAni/PVA–AgNP electrode to the immobilized enzyme promoted efficient catalytic conversion of urea into ammonium and bicarbonate ions. Using the Michaelis–Menten kinetics equation, a KM app of 2.7mmolL−1 was obtained, indicating that the electrode architecture employedmay be advantageous for fabrication of enzymatic devices with improved biocatalytic properties.