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.