Sensitive voltammetric determination of epinephrine in the presence of acetaminophen at a novel ionic liquid modified carbon nanotubes paste electrode

A novel ionic liquid modified carbon nanotubes paste electrode (IL/CNTPE) had been fabricated by using hydrophilic ionic liquid 1-methyl-3- butylimidazolium bromide [MBIDZ]Br as a new binder. The IL/CNTPE was characterized by a scanning electron microscope and voltammetry. Electrochemical behavior of epinephrine (EP) at the IL/CNTPE had been investigated in pH 7.0 phosphate buffer solution (PBS) by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), chronoamperometry (CA) and differential pulse voltammetry (DPV). The experimental results suggested that the modified electrode exhibited an electrocatalytic activity toward the redox of EP. The electron transfer coefficient, diffusion coefficient, and charge transfer resistant (R ct) of EP at the modified electrode were calculated. The IL/CNTPE showed an excellent electrocatalytic activity for selective detection of EP in the presence of acetaminophen (AC) by using DPV. Detection limit of EP and AC was found to be 0.09 and 0.5 μM respectively. The proposed sensor was successfully applied for the determination of EP and AC in human urine, pharmaceutical, and serum samples. © 2012 Elsevier B.V. All rights reserved.