Electrochemical Oxidation and Amperometric Determination of Isoniazid at Functionalized Multiwalled Carbon Nanotube Modified Electrode

In this work we report the fabrication of an electrochemical sensor for the amperometric determination of isoniazid (ISN) based on functionalized multiwalled carbon nanotube (f-MWCNT) modified glassy carbon electrode (GCE). f-MWCNT has been synthesized by acid treatment of MWCNT by ultrasonication. The voltammetric behavior of ISN at various carbon nanomaterials such as MWCNT, f-MWCNT, graphene oxide, reduced-graphene oxide, bare GCE, etc have been studied by cyclic voltammetry (CV). ISN undergoes electrochemical oxidation at all the aforementioned nanomaterials modified electrodes. However, f-MWCNT film modified GCE shows the maximum peak current for ISN among the various carbon nanomaterials, which is 7.11 times higher than that obtained at MWCNT film. ISN undergoes an irreversible oxidation at f-MWCNT film in pH 4 at 0.4V which is well defined and it can be utilized for electroanalytical purposes. ISN showed fast amperometric response at f-MWCNT modified GCE with a good linear range of detection 1 to 70 μM ISN. The film showed good background current stability and excellent performance in pharmaceutical sample analysis with good reproducibility.