Copper oxide nanoleaves covered with loose nickel oxide nanoparticles for sensitive and selective non-enzymatic nitrite sensors

Abstract

In this work, we developed a new method for preparing copper oxide (CuO) nanostructures, designed and prepared a CuONiO modified fluorine-doped SnO2 transparent conductive glass (FTO) electrode for electrochemical sensor to effectively detect the nitrite. The leaf-shaped CuO nanostructures grow uniformly on the FTO electrode, resulting in the increased contact area and reduced transfer resistance. The NiO nanoparticles effectively dispersed in the gaps between the leaves can further improve the electron transfer and reduce the diffusion resistance. The electrochemical results demonstrated that the prepared electrode exhibited high sensitivity (7.2 mA mM−1 cm−2), broad linear range (0.001–1.8 mM) and low detection limit (0.013 μM). Moreover, the prepared sensor also reflected good reproducibility, stability and anti-interference in the detection of actual samples, which provides a good application prospect for metal oxides used in water quality and environmental monitoring.