Sensitive and Stable Voltammetric Measurements of Norepinephrine at Ionic Liquid–Carbon Nanotubes Paste Electrodes

Abstract

The electrochemistry of norepinephrine (NE) was studied by cyclic voltammetry, chronoamperometry and square wave voltammetry (SWV) at a carbon paste electrode modified by multiwall carbon nanotubes (MWNTs) and room-temperature ionic liquid, 1-methyl-3-butylimidazolium chloride (MBIDZCl),. The cyclic voltammogram showed an irreversible oxidation peak at 0.36 V (vs. Ag/AgClsat), which corresponded to the oxidation of NE. Compared to common carbon paste electrode, the electrochemical response was greatly improved. Under the optimized conditions, the oxidation peak current of NE showed linear dynamic range (0.2–500 μmol L–1) with a detection limit of 0.08 μmol L–1, using SWV method. The proposed sensor was successfully applied for the determination of NE in real samples such as drug and urine.