CoFe2O4/reduced graphene oxide/ionic liquid modified glassy carbon electrode, a selective and sensitive electrochemical sensor for determination of methotrexate

In this work, an electrochemical sensor based on CoFe2O4/reduced graphene oxide (rGO) and ionic liquid modified-glassy carbon electrode is fabricated. The modified glassy carbon electrode is used for electrochemical determination of methotrexate, as an anti-cancer drug. Cyclic and differential pulse voltammetry are used as electrochemical techniques to study the electrochemical behavior of methotrexate on the surface of the modified electrode. The results of our study showed that CoFe2O4/IL-rGO nanocomposite has synergetic effect on the oxidation of methotrexate, by decreasing the oxidation overpotential and increasing the oxidation peak current. After optimization of the experimental and instrumental conditions, using the proposed electrochemical sensor, methotrexate can be measured in the range of 0.05-7.5 nmol mL(-1) with a limit of detection of 0.01 nmol mL(-1). Relative standard deviation for five replicates measurements of 2.0 nmol mL(-1) methotrexate was 4.5%. The selectivity and applicability of the proposed electrochemical sensor toward methotrexate were investigated using analysis of pharmaceutical tablets with satisfactory results. (C) 2017 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.