Abrasive immobilization of carbon nanotubes on a basal plane pyrolytic graphite electrode: application to the detection of epinephrine

The performance of a basal plane pyrolytic graphite (bppg) electrode modified with carbon nanotubes is described. Abrasive immobilization of multiwall carbon nanotubes on a bppg electrode was achieved by gently rubbing the electrode surface on a filter paper supporting carbon nanotubes. The resulting electrode showed excellent mediation of epinephrine oxidation: a decrease in the overvoltage of the epinephrine electro-oxidation ( 200 - 500 mV) was observed as well as a dramatic increase in the peak current ( 4 times) compared to that seen at a bare bppg electrode. The oxidation peaks of epinephrine and ascorbic acid which overlap on bare bppg electrode were separated successfully ( by ca. 220 mV) at the surface of the modified bppg electrode. The modified electrode showed good stability in comparison to most modified carbon nanotubes electrodes prepared by alternative methods.