Integrating electrochemical sensor based on MoO₃/Co₃O₄ heterostructure for highly sensitive sensing of nitrite in...

Considering excess nitrites are detrimental to the human body and environment, designing a rapid, sensitive, and real-time quantitative determination for nitrite is of great significance for environmental preservation and public health. In this paper, Co₃O₄ nanoflowers coupled with ultrafine MoO₃ nanoparticles (MoO₃/Co₃O₄) are obtained via a hybrid electrochemical deposition strategy (HED). The as-designed MoO₃/Co₃O₄/CC integrating electrode exhibits superior electrocatalytic properties towards nitrite oxidation, owing to the synergistic effect between MoO₃ and Co₃O₄ caused by the heterostructure of MoO₃/Co₃O₄. The electrode achieved a low response time of 2 s, an excellent sensitivity of 1704.1 μA mM^-1 cm^-2, and a low limit of detection of 0.075 μM (S/N = 3). Furthermore, the electrode displays promise for nitrite detection in complex food such as water and sausages samples. Our study will provide a significant strategy for the application of bimetallic heterostructure to explore the design of sensing interfaces.