Screen-printed enzyme electrodes using microcapsules containing glucose oxidase and mediator

Polyamide microcapsule containing glucose oxidase (GOD) and tetrathiafulvalene (TTF) was prepared for the application to a molecular recognition element of screen-printed enzyme electrode. The microcapsules were entrapped in a polyion complex film or a carbon ink containing TTF, and then immobilized directly on the screen-printed carbon electrodes. The enzyme activity of the microcapsule was evaluated by the cyclic voltammetry in a phosphate buffer solution containing glucose. The enzyme electrodes were active to oxidize the dissolved glucose which is catalyzed by the entrapped GOD. In addition, the electroactive TTF molecules were proved to penetrate the poly-amide membrane and to function as a mediator.