A stable and well-distributed nitrogen-doped graphene (NGE) is prepared by a simple and efficient hydrothermal method with a reducing-doping reagent of vitamin B3. Compared with NGE reduced by urea, vitamin B3 reduced NGE (NGE-N) showsuperior catalysis towards the electrochemical reduction of imidacloprid. The pyridine-N oxide induced in graphene sheets is considered enhancing the interaction between NGE-N and imidacloprid molecules. The NGE-N modified electrode is used in fast determination of imidacloprid with a low detection limit of 0.55 mu M. (C) 2016 Elsevier Ltd. All rights reserved.