Measuring dopamine levels is very important for the diagnosis and prevention of many neurological and mental diseases like Parkinson's disease, Alzheimer's disease, Huntington's, attention deficit hyperactivity disorder, Tourette's syndrome, depression etc. One of the best approaches to measure dopamine levels is through electrochemical sensors. A nano-structure-based electrochemical sensor was fabricated for dopamine detection.

 In this study, graphene oxide was electrochemically deposited and reduced on a graphite sheet. The electrode surface morphology was studied via scanning electron microscopy (SEM). The performance of the modified electrode in the detection of dopamine was investigated. The results show that the addition of reduced graphene oxide (rGO) on the electrode surface increases the dopamine oxidation current, decreases the overpotential, and reduces the charge transfer resistance. The efficiency of dopamine detection using this modified electrode was evaluated via cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The influence of the electrolyte pH, potential scan rate, electrode reproducibility, and selectivity was investigated. Also, for the stability test, the chronoamperometry (CA) technique was used and the results showed that the electrode has a good stability. The detection limit of this electrode was 68 nM and the linear range was 10-7 to 10-4 M. For real sample analysis, determination was achieved successfully in a dopamine ampoule. The preparation of this modified electrode is easy, fast and very cost-effective. The results illustrates that this sensor is competent enough for dopamine detection in real circumstances. It is worth mentioning that despite not using expensive materials in this work, its detection limit and linear range are significantly comparable with other reports.