Functionalised multi-walled carbon nanotubes (MWCNT) were homogenised in the room temperature ionic liquids (RTILs) 1-butyl-3-methylimidazolium bis(trifluoromethane)sulfonimide (BmimNTF(2)), 1-butyl-1-methylpyrrolidinium bis(trifluoromethane)sulfonimide (BmpyNTF(2)) and 1-butyl-3-methylimidazolium nitrate, and the composite obtained was applied on the top of glassy carbon or carbon film electrode substrates. The modified electrodes were characterised electrochemically in aqueous electrolytes and ionic liquids using cyclic voltammetry and electrochemical impedance spectroscopy and the model redox couples potassium hexacyanoferrate and ferrocene were used for electrode characterisation in aqueous and RTIL media, respectively. It was found that the combination of MWCNT with BmimNTF(2) gave the best composite which augurs well for application in sensors and biosensors. (C) 2009 Elsevier B.V. All rights reserved.