Fe3O4 nanoparticles decorated reduced graphene oxide&carbon nanotubes-based composite for sensitive detection of imatinib in plasma and urine

In this study, a new reduced graphene oxide (rGO) has been synthesized via a facile and envi­ronmentally friendly process using Callicarpa maingayi leaf extract. A novel magnetic catalyst based on Fe3O4 nanoparticles-reduced graphene oxide&carbon nanotubes ((Fe3O4--(rGO&CNT)) was prepared and characterized by hydrothermal method. The Fe3O4 nanoparticles with an average size of 25 to 40 nm were placed on carbon nanotubes and reduced graphene oxide sheets, while carbon nanotubes inserted between the reduced graphene oxide sheets effectively prevented their aggregation. The (Fe3O4-(rGO&CNT) composite has a large surface area and good electrocatalytic properties, suiting for the detection and determination of imatinib (IM) anticancer drug by voltammetry method. Under opti­mi­zed conditions, good linearity was achieved in the concentration range of 0.1 to 40 μmol L-1 and the limit of detection and sensitivity were 57 nmol L-1 and 3.365 μA L μmol-1, respectively. Furthermore, the fabricated sensor demonstrated acceptable reproducible behaviour and accuracy and a high level of stability during all electrochemical tests. In addition, the proposed method was applied for the detection of IM in biological samples and the recoveries were 94.0 to 98.5 %, with relative standard deviations of 2.1 to 4.4 %.