Abstract

A modified electrode using fullerene-functionalized carbon nanotubes and ionic liquid (IL, 1-butyl-3-methylimidazolium tetrafluoroborate) has been applied for the determination of diazepam in real samples including serum, urine, and tablets. The properties of fullerene-functionalized carbon nanotubes and ionic liquid were characterized by transmission electron microscopy, scanning electron microscope, electrochemical impedance spectroscopy, and voltammetry. The experimental results confirmed that modified electrode with fullerene-functionalized carbon nanotubes and ionic liquid has good electrocatalytic activity toward the reduction of diazepam. The electrocatalytic current increases linearly with the diazepam concentration in the ranges of 0.3-700.0 mu M, and the detection limit is 87 +/- 2 nM. The proposed electrode displayed excellent repeatability and long-term stability and it was satisfactorily used for determination of diazepam in real samples (commercially tablet, urine, and serum samples) with high recovery. (C) 2016 Elsevier B.V. All rights reserved.