Simultaneous Determination of Dopamine and Paracetamol using a Gold Electrode Modified with MWCNTs/GO Nanocomposite Capped Au Nanoparticles

In this research project, a sensitive electrochemical sensor was developed for simultaneous voltammetric determination of dopamine (DA) and paracetamol (PA) based on a gold electrode modified with functionalized multi-wall carbon nanotubes/graphene oxide (f-MWCNTs/GO) nanocomposite capped with gold nanoparticles (AuNPs). The modified electrode showed excellent electrocatalytic activity for the oxidation of DA and PA molecules in aqueous solutions with well-separated oxidation peaks for each species. The fabrication process of the proposed sensor was evaluated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Cyclic voltammetry (CV) and also electrochemical impedance spectroscopy (EIS) were used to investigate the electrochemical properties of f-MWCNTs/GO/AuNPs/AuE. Under the optimized experimental conditions, the calibration curves were linear over the concentration ranges of 1-400 µM with a detection limit of 0.5 and 0.3 µM for DA and PA, respectively. Finally, the constructed electrode was successfully applied for the quantitative measurement of dopamine and paracetamol in pharmaceutical and urine samples.