An ionic liquid-Fe3O4 nanoparticles-graphite composite electrode used for nonenzymatic electrochemical determination of hydrogen peroxide

•Ionic liquid and Fe3O4 nanoparticles are combined to form composite electrode.•Costly materials and complicated techniques are not needed.•Combination of ionic liquid and Fe3O4 nanoparticles show synergistic effects.•The synergistic effects display on the high sensitivity toward H2O2 reduction.

In this study, an ionic liquid-Fe3O4 nanoparticles-graphite composite electrode (IL-Fe3O4NPs-GP) with high sensitivity was fabricated using easy-to-made materials and convenient techniques. A hydrophobic ionic liquid 1-butyl-1-methylpyrrolidinium bis((trifluoromethyl)sulfonyl)amide (IL BMP-TFSA) was used to substitute paraffin oil that is conventionally used as the organic binder for preparing carbon paste electrodes. Fe3O4NPs show pseudo-peroxidase activity toward hydrogen peroxide (H2O2) that was electrocatalytically reduced at the electrode. This electrode shows the synergistic effect from the combination of IL and Fe3O4NPs, exhibiting a high sensitivity of 200.7 μA mM−1 cm−2 but a narrower dynamic range of 1–25 μM with a detection limit of 0.5 μM. This electrode also shows good stability and several common interferents show negligible effect on the determination of H2O2.