Carbon-nanotubes doped polypyrrole glucose biosensor

We report on the one-step preparation route of amperometric enzyme electrodes based on incorporating a carbon-nanotube (CNT) dopant and the biocatalyst within an electropolymerized polypyrrole film. Cyclic voltammetric growth profiles indicate that the anionic CNT is incorporated within the growing film for maintaining its electrical neutrality. The entrapment of the CNT has little effect upon the electropolymerization rate and redox properties of the resulting film. The CNT dopant retains its electrocatalytic activity to impart high sensitivity and selectivity. Linearity prevails up to ca. 50 mM glucose, with a slight curvature thereafter. Relevant parameters of the film preparation were examined and optimized. Such an electropolymerization avenue represents a simple, one-step route for preparing enzyme electrodes and should further facilitate the widespread production of CNT-based electrochemical biosensors.