Simultaneous electrochemical determination of epirubicin and methotrexate in human blood using a disposable electrode modified with nano-Au/MWNTs-ZnO composites

A novel nano-Au/MWNTs-ZnO modified screen printed electrode (SPE) was fabricated for directly simultaneous determination of epirubicin (EPI) and methotrexate (MTX) in whole blood samples. Electrochemical performances of the modified electrode were greatly enhanced due to the presence of nano-Au/MWNTs-ZnO nanocomposites. The optimum experimental conditions for the detection were explored, and the currents of EPI and MTX measured by SWV presented a good linear property with the increasing of the concentrations. Under optimized conditions, the linear ranges of EPI and MTX were determined to be 0.005–0.200   μM and 0.02–1.00   μM, with the detection limits of 2.5   nM and 10   nM, respectively. Furthermore, the nano-Au/MWNTs-ZnO SPE was applied for simultaneous determination of EPI and MTX in pharmaceutical injections and diluted human blood samples with wonderful satisfactory results.