Sensitive Electrochemical Detection of Dopamine With a Nitrogen-doped Graphene Modified Glassy Carbon Electrode

In this paper nitrogen-doped graphene (NG) nanosheets were used as the modifier on the surface of glassy carbon electrode (GCE). The modified electrode (NG/GCE) was further applied to the sensitive detection of dopamine (DA) by voltammetric method. Due to the unique properties of NG such as large surface area and excellent electrocatalytic activity, electrochemical response of DA was greatly enhanced on NG/GCE with a pair of well-defined redox peaks appeared on cyclic voltammogram. Electrochemical behaviors of DA on NG/GCE were carefully investigated with the electrochemical parameters calculated. Under the selected conditions the oxidation peak currents of DA had a good linear relationship with its concentration in the range from 8.0 ×10–7 mol L–1 to 8.0 ×10–4 mol L–1 with a detection limit of 2.55 ×10–7 mol L–1 (3σ). The proposed method was further applied to the DA injection samples determination with satisfactory results.