Voltammetric behavior of a multi-walled carbon nanotube modified electrode-ferrocene electrocatalyst system as a sensor for determination of methyldopa in the presence of folic acid

The study of electrochemical behavior and determination of methyldopa (MD) is reported for a carbon nanotube (CNT) modified carbon-paste electrode (CPE) and ferrocene (FC) electrocatalyst. The cyclic voltammetric results indicate that the CNT and FC system can remarkably enhance electrocatalytic activity toward the oxidation of MD. This enhancement leads to a considerable improvement of the anodic peak current for MD, and allows the development of a highly sensitive voltammetric sensor for the detection of MD in real samples. Under optimized conditions on the sensor, the proposed method shows a wider dynamic range (0.1–500 μM) in comparison to other reported electrochemical methods, with a detection limit of 0.08 ± 0.002 μM. In addition, the proposed method was able to determine MD in the presence of folic acid (FA).