A novel electrochemical sensor for non-ergoline dopamine agonist pramipexole based on electrochemically reduced graphene oxide nanoribbons

A facile and feasible electrochemical sensing platform based on electrochemically reduced graphene oxide nanoribbons (ERGONRs) was designed for electrochemical investigations and determination of a non-ergoline dopamine agonist, pramipexole dihydrochloride monohydrate (PPX), in pharmaceutical formulations and biological fluids. Newly synthesized graphene oxide nanoribbons were characterized by SEM, AFM, XRD and EDX. The solution of graphene oxide nanoribbons (GONRs) was placed on a glassy carbon electrode (GCE) and reduced electrochemically in phosphate buffer solution of pH 6 to obtain the electrochemically reduced graphene oxide nanoribbon modified glassy carbon electrode (ERGONR-GCE). Significant electrooxidation of PPX was observed at the ERGONR-GCE in phosphate buffer of pH 6.0 compared to that at the bare GCE. The effect of accumulation time, pH and scan rate was studied and various electrochemical parameters were evaluated. The plot of pH versus E_p yielded a slope of 57.65 mV per pH in the pH range of 3.0-8.0 indicating the participation of an equal number of electrons and protons in the electrode process. A differential pulse voltammetric method was developed for the determination of PPX in bulk, pharmaceutical formulations and urine samples. PPX showed a linear relationship between the peak current and the concentration in the range of 0.01-15 μM with a LOD of 2.8 nM and a LOQ of 9.4 nM. The fabricated electrode also showed good selectivity and excellent sensitivity. The proposed method is simple, rapid and inexpensive and hence could be readily adopted for the analysis of PPX. The results were subjected to statistical analysis.