A novel morphology of 3D graphene hydrogel nanotubes for high-performance nonenzymatic hydrogen peroxide sensor

A novel nanostructure of three-dimensional graphene hydrogel nanotubes (3DGHNTs) is successfully synthesized for the purpose of sensing non-enzymatic H₂O₂ in alkaline solution. The 3DGHNTs were fabricated using manganese dioxide nanotubes (MnO₂ NTs) as the effective sacrificial template and without the use of any acids or a high temperature process. 3DGH with different percentages of MnO₂ NTs ranging from 5 to 30% are prepared via a hydrothermal method. When the loading percentage of MnO₂ NTs is 10%, the obtained 3DGHNTs-Mn10 nanocomposite exhibits a large specific surface area with high porosity, which enhance the electrochemical properties for H₂O₂ detection. The developed biosensor exhibits excellent sensitivity (220.4 μA mM⁻¹ cm⁻²) with a wide linear detection range (25 μM–22.57 mM) and a low detection limit (4 μM). The biosensor also shows a fast response time (less than 5 s) and good selectivity as well as reproducibility and long-term stability. Hence, the prepared 3DGHNTs-Mn10 nanocomposite can be considered a promising electrode material for the detection of H₂O₂ in real sample.