Visible light-assisted photoelectrochemical sensing platforms based on the hierarchical architectures of 3D Ni-graphene@au skeletons for H2O2 detection in human serum

Hydrogen peroxide (H₂O₂), one of the reactive oxygen species (ROS), is closely linked to carcinogenesis and tumor progression, making sensitive and accurate detection essential for early disease diagnosis. In this study, plasmonic Au nanoparticles were integrated into an interconnected 3D porous Ni–graphene framework to construct hierarchical Ni–graphene@Au conductive skeletons. The material was synthesized through a simple one-step electrodeposition method to improve both efficiency and sensitivity of H₂O₂ detection. The engineered architecture functions as a photoelectrochemical sensing platform, where the strong localized surface plasmon resonance (LSPR) effect of Au nanoparticles enables efficient light harvesting under plasmonic excitation and significantly enhances photoelectrochemical performance. Enhancement arises from the synergistic interaction between LSPR-active Au nanoparticles and the highly conductive 3D porous Ni–graphene network, which provides an enlarged photoelectroactive surface area and facilitates rapid charge transport. Under light-assisted conditions, the Ni–graphene@Au sensor exhibited a strong photoelectrocatalytic response toward H₂O₂ detection. When applied to diluted human serum samples, the sensor delivered a linear response in the 0.1–1.0 mM range, with excellent sensitivity (0.1197 mA mM⁻¹ cm⁻²) and a low limit of detection (33.5 μM). The demonstrated performance highlights superior analytical capability in real biological environments. Overall, the outstanding photoelectrochemical properties of the Ni–graphene@Au architecture indicate strong potential for clinical implementation in H₂O₂ sensing, particularly for early disease diagnosis.