▎ 摘　　要

In this study, a novel theophylline (TP) sensor based on MnO2 nanosheets/ionic liquid-functionalized graphene (MnO2 nanosheets/IL-graphene) was fabricated. Cyclic voltammetry (CV) was used to evaluate the electrochemical behavior of the modified electrode. The surface concentration of the electroactive species, Gamma, was calculated to be approximately 2.316 x 10(-10) mol cm(-2) for MnO2 nanosheets on the modified electrode. The resulting system was suitable for electrochemical sensing because of the combined advantages of MnO2 nanosheets and IL-graphene. The differential pulse voltammetric (DPV) results indicated a high ability of the MnO2 nanosheets/IL-graphene/GCE to catalyze the oxidation of TP and, hence, to detect it. DPV determination of TP gave linear responses over the concentration range from 1 to 220 mu M, and the detection resolution limit was 0.1 mu M. Furthermore, the applicability of the MnO2 nanosheets/IL-graphene/GCE for analysis in real samples was successfully demonstrated. (C) 2017 Elsevier B.V. All rights reserved.