Copper oxide decorated nitrogen-doped rGO toward sensitive non-enzymatic hydrogen peroxide detection

Hydrogen peroxide (H₂O₂) is endogenously generated by enzyme-triggered pathways and cellular metabolism, and its dysregulated accumulation is causally implicated in the initiation and progression of a broad spectrum of human diseases. Therefore, the accurate quantification of H₂O₂ is an indispensable analytical task. Herein, reduced graphene oxide was employed as the carbon precursor, aniline as the nitrogen source, and anhydrous copper (II) acetate as the copper provider to fabricate, via a one-pot protocol, an N-doped reduced graphene oxide/CuO (N-rGO/CuO) intermediate. Subsequent hydrazine etching produced an N-rGO/CuO composite exhibiting high sensitivity and selectivity toward H₂O₂. The microstructure, morphology, optical properties, elemental composition, and electrochemical characteristics of the material were systematically investigated. Amperometric measurements revealed a linear current response to H₂O₂ over the concentration range 10–3000 μM (R 2  = 0.992), a sensitivity of 1.6524 μA·mM −1 ·cm −2 , and a limit of detection (LOD) of 0.129 μM. These performance metrics demonstrate that the proposed biosensor possesses satisfactory selectivity, reproducibility, repeatability, and long-term stability.