Voltammetric Determination of Penicillamine Using a Carbon Paste Electrode Modified with Multiwall Carbon Nanotubes In the Presence of Methyldopa as a Mediator

Document Type: Research article


1 Young Researcher and Elite Club, Majlesi Branch, Islamic Azad University, Isfahan, Iran

2 Department of Chemistry, Majlesi Branch, Islamic Azad University, Isfahan, Iran

3 Department of Chemical Engineering, Laboratory of Nanotechnology, Quchan University of Advanced Technology, Quchan, Iran.


A multiwall carbon nanotubes-modified carbon paste electrode (MWCNTs/MCPE) was
fabricated and used to study the electrooxidation of penicillamine (PA) by electrochemical
methods in the presence of methyldopa (MDOP) as a homogeneous mediator. The
electrochemical oxidation of PA on the new sensor has been carefully studied. The kinetic
parameters such as electron transfer coefficient, α, and catalytic reaction rate constant, K/
h, were also determined using electrochemical approaches. The electrocatalytic oxidation peak current
of PA showed a linear dependent on the PA concentrations and linear calibration curves were
obtained in the ranges of 0.2-250.0 μM of PA concentration with square wave voltammetry
(SWV) method. The detection limit (3σ) was determined as 0.1 μM. This sensor was also
examined as a fast, selective, simple and precise new sensor for voltammetric determination of
PA in real samples such as drug and urine.


Main Subjects