Electrochemical Determination of Methyldopa by Graphene Quantum Dot / 1-butyl-3-methylimidazolium hexafluoro phosphate Nanocomposite Electrode

Methyldopa is one the important catecholamines used for treatment of high blood pressure. In this study, a nanocomposite electrode was made using graphene quantum dots (GQD) and 1-butyl-3-methylimidazolium hexafluorophosphate (1B3MIPF(6)) in a carbon paste matrix (GQD/1B3MIPF(6)/CPE). The used GQD was synthesized and characterized using transmission electron microscopy (TEM). The electro-oxidation behavior of Methyldopa was investigated on the surface of GQD/1B3MIPF(6)/CPE and finally it was used as a working electrode for the electrochemical determination of Methyldopa in some pharmaceutical and biological samples. The results showed an improvement of similar to 3.2 times in electro-oxidation peak of methyldopa in a dynamic linear range of 0.04-750.0 mu M (limit of detection 0.01 mu M).