Optical and bioelectrochemical characterization of water-miscible ionic liquids based composites of multiwalled carbon nanotubes

Abstract

Acidic treated multiwalled carbon nanotubes (AMWNTs) were ground with water-miscible room temperature ionic liquids, 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4), and resulted in AMWNTs-[bmim]BF 4 composite. Its electrical-ionic conductivity and optical properties were compared with the other two types of carbon materials-[bmim]BF4 composites: pyrolytic graphite powder (PGP), pristine multiwalled carbon nanotubes (PMWNTs), through the ac impedance technology and Raman spectroscopy. The impedance data show that AMWNTs-[bmim]BF4 composite exhibits the highest conductivity. Raman spectra study exhibits that the [bmim]BF4 can form gel with PMWNTs and AMWNTs but only form a viscous liquid with PGP. AMWNTs-[bmim]BF4 gel modified GC electrode was applied in direct electrochemistry of heme proteins (Hb and HRP) and it catalysis to the reduction of H2O2 was investigated. © 2006 Wiley-VCH Verlag GmbH & Co. KGaA.