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

• The MoO 3 /Co 3 O 4 heterostructure was formed via a hybrid electrochemical deposition strategy. • The synergistic effect of Co 3 O 4 and MoO 3 plays a predominant role in nitrite electrooxidation. • The MoO 3 /Co 3 O 4 /CC has been successfully used in food samples for nitrite detection. 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, Co 3 O 4 nanoflowers coupled with ultrafine MoO 3 nanoparticles (MoO 3 /Co 3 O 4) are obtained via a hybrid electrochemical deposition strategy (HED). The as-designed MoO 3 /Co 3 O 4 /CC integrating electrode exhibits superior electrocatalytic properties towards nitrite oxidation, owing to the synergistic effect between MoO 3 and Co 3 O 4 caused by the heterostructure of MoO 3 /Co 3 O 4. 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. [ABSTRACT FROM AUTHOR]