Construction and analytical characterization of Prussian Blue-based carbonpaste electrodes and their assembly as oxidase enzyme sensors

This paper reports on the development and characterization of Prussian Blue -modified carbon paste electrodes. New methods of matrix modification with Prussian Blue are reported. Two different carbon pastes have been prepared, using mineral oil or solid paraffin, thus obtaining different types of sen sors whose behavior toward the electrochemical reduction of hydrogen peroxi de has been fully characterized. Results obtained with Prussian Blue-modifi ed electrodes showed a long operational lifetime, an excellent stability in a nide range of pH (3-9), a high sensitivity, and a fast response time. In addition, the coupling of solid carbon paste modified with Prussian Blue a nd the enzymes glucose oxidase and choline oxidase led to the assembling of biosensors that showed an optimum working range at alkaline pH.