▎ 摘　　要

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 HQand CC, the linear ranges for HQand CC were 4.0 similar to 600 mu M and 6.0 similar to 400 mu M respectively, and the detection limit was 0.40 mu M and 0.75 mu M, respectively. The modified electrode was also applied for the detection of real samples with satisfactory results. (C) 2016 Elsevier Ltd. All rights reserved.