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

A multiwall carbon nanotubes-modified carbon paste electrode (MWCNTs/MCPE) wasfabricated and used to study the electrooxidation of penicillamine (PA) by electrochemicalmethods in the presence of methyldopa (MDOP) as a homogeneous mediator. Theelectrochemical oxidation of PA on the new sensor has been carefully studied. The kineticparameters such as electron transfer coefficient, α, and catalytic reaction rate constant, K/h, were also determined using electrochemical approaches. The electrocatalytic oxidation peak currentof PA showed a linear dependent on the PA concentrations and linear calibration curves wereobtained 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 alsoexamined as a fast, selective, simple and precise new sensor for voltammetric determination ofPA in real samples such as drug and urine.