Defect-rich CuO nanosheets for sensitive non-enzymatic electrochemical detection of hydrazine

Hydrazine (N₂H₄) is a highly toxic but widely used industrial chemical, and its rapid detection is of great importance for environmental and safety monitoring. In this work, defect-rich CuO nanosheets were synthesized by a facile chemical precipitation method and used to fabricate a non-enzymatic electrochemical sensor for hydrazine detection. Structural characterization revealed that the obtained CuO possessed a sheet-like porous morphology with abundant defect sites, which is favorable for interfacial charge transfer and electrocatalytic N₂H₄ oxidation. The CuO-modified glassy carbon electrode exhibited excellent electrocatalytic activity toward hydrazine oxidation in alkaline medium, a wide linear range of 0.001-5.55 mM, a low detection limit of 0.58 μM, a high sensitivity of 510.65 μA mM^-1 cm^-2, and satisfactory stability. The enhanced sensing performance was attributed to the synergistic effects of the porous nanosheet structure and defect-rich surface. This work provides a simple strategy for constructing CuO-based sensing materials and demonstrates their promising potential for non-enzymatic hydrazine detection.