Differential Pulse Voltammetric Determination of Methyldopa Using MWCNTs Modified Glassy Carbon Decorated With NiFe2O4 Nanoparticles, Ali A. Ensafi, B. Saeid, B. Rezaei, Ali R. Allafchian, Ionics, 2015, 21, 1435-1444.
A nanosensor was introduced for a sensitive determination
of methyldopa using multiwall carbon nanotubes
(MWCNTs) decorated with ferrite nickel nanoparticles
(NiFe2O4) on a glassy carbon electrode. The electrochemical
activity of the modified electrode for the determination of
methyldopa was investigated using differential pulse voltammetry,
cyclic voltammetry, and electrochemical impedance
spectroscopy. The results showed that the modified electrode
exhibits synergistic activity to the oxidation of methyldopa.
The influence of several parameters that affect the response of
the modified electrode was studied. A wide linear dynamic
range of 0.5 to 900 μmol L−1 methyldopa with a detection
limit of 0.08 μmol L−1 was achieved using differential pulse
voltammetry. The interference of foreign substances on the
selectivity of the electrochemical sensor was evaluated. Finally,
the proposed method was successfully applied for the
determination of methyldopa in real samples such as human
urine, tablet, and plasma with satisfactory results.