DataSheet1_New Methylene Blue Covalently Functionalized Graphene Oxide Nanocomposite as Interfacial Material for the Electroanalysis of Hydrogen Peroxide.docx

New methylene blue (NMB), a phenothiazine dye, was covalently bonded to graphene oxide (GO) using glutaraldehyde as a crosslinking agent, which was characterized by spectroscopic techniques and electrochemistry. The obtained GO–NMB nanocomposite was used as interface material to construct a novel electrochemical sensor for the determination of hydrogen peroxide (H2O2). The electrochemical sensor based on GO–NMB nanocomposite exhibited excellent electrocatalytic activity for the reduction of hydrogen peroxide (H2O2), which was also enhanced by GO within the GO–NMB nanocomposite. With the optimized experimental conditions, the developed sensor showed high sensitivity (79.4 μA mM−1 cm−2) for electrocatalytic determination of H2O2 at the applied potential of −0.50 V in the concentration range of 0.000333 to 2.28 mΜ. The low limit of detection (1.35 μM), good reproducibility, and high stability of the sensor suggests that the electrochemical sensor based on the GO–NMB nanocomposite possesses obvious advantages, which paves a new avenue to functionalize GO for obtaining electrode interface materials.新亚甲基蓝（New methylene blue, NMB）是一种吩噻嗪类染料，本研究以戊二醛为交联剂，将其共价键合至氧化石墨烯（graphene oxide, GO）表面，并通过光谱技术与电化学手段对产物进行了表征。所得GO-NMB纳米复合材料被用作界面材料，构建了一种用于过氧化氢（hydrogen peroxide, H₂O₂）检测的新型电化学传感器。基于该GO-NMB纳米复合材料的电化学传感器对过氧化氢的还原表现出优异的电催化活性，且GO-NMB复合材料中的氧化石墨烯组分进一步强化了该催化性能。在优化后的实验条件下，所构建的传感器在施加电位-0.50 V、过氧化氢浓度范围为0.000333~2.28 mM时，对过氧化氢的电催化检测展现出较高的灵敏度（79.4 μA·mM⁻¹·cm⁻²）。该传感器具备低检出限（1.35 μM）、良好的重现性与较高的稳定性，表明基于GO-NMB纳米复合材料的电化学传感器具有显著优势，为氧化石墨烯的功能化改性以制备电极界面材料开辟了全新路径。