Comparative studies of hybrid functional materials based on different carbon structures decorated with nano-magnetite. Suitable application as platforms for enzyme-free electrochemical sensing of hydrogen peroxide

The electro-catalytic behavior of modified glassy carbon electrodes, using magnetite-graphite hybrids exhibited an enhanced catalytic ability toward H2O2 reduction. The best response was obtained using graphites with smaller particle sizes (2 μm and 17 μm), modified with nano-magnetite. The performance of the electrode in terms of sensitivity for H2O2 amperometric detection was (1.1 ± 0.1) × 105 μA M−1 cm−2 mg−1 while the LOD was 0.50 nM at a working potential of −0.200 V. These values are comparable to those obtained using carbon nanotubes and metal or metal-oxide based sensors. The new proposed material appears as a very promising alternative for H2O2 non-enzymatic sensors mainly because its low cost and abundance. The comparison between the different carbon substrates highlights the importance of the close contact between carbon and nano-magnetite, which enhances the catalytic behavior of the material.