Electrochemical detection of hydrogen peroxide by ZnO-based materials and multiphysical parameter regulation of Ni-substituted ZnO

The development of highly sensitive electrochemical sensors for rapid and accurate quantification of hydrogen peroxide (H 2 O 2 ) is of great significance in biological, clinical, and various other fields. However, there remains insufficient understanding of how to optimize material structures to enhance sensing performance and the mechanisms by which physical parameter regulation influences sensing properties. In this work, we report the growth of micron-scale, Ni-substituted needle-shaped ZnO arrays on a flexible interdigitated electrode substrate, achieved through the initial synthesis of a nanostructured ZnO seed layer. Electrochemical experiments revealed that Ni-substituted ZnO exhibits superior H 2 O 2 sensing performance compared to needle-shaped ZnO arrays and the ZnO seed layer. The incorporation of Ni significantly reduces the resistivity, increases the specific surface area, and enhances the adsorption of oxygen species. Importantly, we employed multiple physical parameters, including magnetic field, UV illumination, and mechanical strain, to regulate the H 2 O 2 sensing performance of Ni-substituted ZnO, and clarified the underlying physical mechanisms behind these regulations. In short, our ZnO-based flexible materials provide a promising approach for non-invasive, real-time H 2 O 2 monitoring, holding strong potential for wearable medical devices and point-of-care applications.