Oxygen Plasma Exfoliated Vertically-Aligned Carbon Nanotubes as Electrodes for Ultrasensitive Stripping Detection of Pb2+

In the present paper we report the production of vertically aligned carbon nanotubes exfoliated (at the tips) by oxygen plasma for electrochemical applications. The fast and dry process produces graphene oxide tips and oxygen functionalization The electrodes are evaluated by cyclic voltametry by ferri/ferrocyanide redox couple and applied for electrochemical detection of lead (II) by differential pulsed anodic stripping voltammetry. The electrode presents high sensitivity (35.47 uA.uM(-1)) and low detection limit (48.3 pM). As far as we know, this is the lowest LoD in comparison with other works using CNT or graphene electrodes. The high electrochemical response is attributable to high density of functionalized edges on carbon nanotubes tips. (C) 2014 The Electrochemical Society. All rights reserved.