Treated Screen Printed Electrodes Based on Electrochemically Reduced Graphene Nanoribbons for the Sensitive Voltammetric Determination of Dopamine in the Presence of Uric Acid

In this research, the graphene oxide nanoribbons (GONRs) were substantially synthesized by the oxidative longitudinal unzipping of the multi-walled carbon nanotubes (MWCNTs). Then, a direct electrochemical technique was employed for reducing GONRs adsorbed on the screen printed carbon electrode (SPCE). Electrochemical reduction effectively eliminated the oxygen-containing groups in the GONRs and produced the electrochemically reduced graphene nanoribbons (ERGNRs). Field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) were employed to characterize the materials. The modified SPCE with ERGNRs (ERGNRs/SPCE) displayed acceptable electrocatalytic characteristics towards the oxidation of dopamine (DA) and uric acid (UA) and applied to the simultaneous determination of these two analytes. ERGNRs/SPCE has a peak potential difference of 245 mV between DA and UA. The anodic peak currents of DA and UA were linear within the concentration ranges between 0.5 and 300.0 mu M and 1.0 to 400.0 mu M in phosphate buffer (pH=7.0) respectively. The detection limit of the technique for DA is 0.15 mu M (S/N=3) and for UA is 0.3 mu M (S/N=3). The proposed approach has been applied to the determination of DA and UA in real samples and generated acceptable outputs.