Graphene quantum dots modified glassy carbon electrode via electrostatic self-assembly strategy and its application

An electrostatic self-assembly strategy for the preparation of graphene quantum dots (GQDs) attached to the surface of a glassy carbon electrode (GCE) has been developed. The GQDs were prepared by tuning the carbonization degree of citric acid and characterized by atomic force microscopy, transmission electron microscopy, Raman spectroscopy and UV-vis absorption spectroscopy. In addition, the electrochemical behaviours of hydroquinone (HQ) and catechol (CC) on the resulting modified electrodes were investigated. Under optimum conditions, the as-prepared GQDs modified electrode exhibited high electrochemical activity and good selectivity for the oxidation of HQ and CC, the linear ranges for HQ and CC were 4.0∼600 μM and 6.0∼400 μM respectively, and the detection limit was 0.40 μM and 0.75 μM, respectively. The modified electrode was also applied for the detection of real samples with satisfactory results.