Double-walled carbon nanotube electrodes for electrochemical sensing

We report on the electrochemical properties of electrodes fabricated using spun fibers of purified double-walled nanotubes (DWNTs). These electrodes show reversible and faster electron-transfer kinetics in electrochemical reactions compared to multiwalled nanotubes (MWNTs) and standard glassy carbon electrodes (GCE). The detection capabilities of the DWNT electrodes for chemical species such as hydrogen peroxide, ascorbic acid (AA), and electroactive neurotransmitters such as dopamine are presented and compared with the detection abilities for these species using GCE and MWNT. These electrodes also show excellent selective sensing properties (with observed detection limits as low as 20 mu M of DA in 1 mM of AA) and can be developed for active components in electrochemical sensors. (c) 2007 The Electrochemical Society.