Polyethylenimine Functionalized Multi-walled Carbon Nanotubes for Electrochemical Detection of Chromium(VI)

Multi-walled carbon nanotubes (MWCNTs) functionalized with polyethylenimine (PEI) were synthesized and characterized by dispersibility, field-emission scanning electron microscope (FE-SEM), FT-IR and thermogravimetric Analyzer (TGA). The glassy carbon electrodes modified by MWCNT-PEI composite were used for sensitive and selective detection of chromium (VI). A linear response was obtained over a wide range of Cr(VI) concentrations (0.002–20 µmol L −1 ) with the detection limit of 0.0006 µmol L −1 (S/N=3). The proposed electrodes were used successfully for Cr(VI) detection in three real water samples.