Abstract: In order to develop a method for rapid determination of nitrite in meat products, Cu-based metal organic frameworks (Cu-MOFs) were synthesized electrochemically, which were found to be uniformly distributed on the surface of a glassy carbon electrode (GCE). The scanning electron microscopic (SEM) images exhibited that Cu-MOF particles were octahedral. NO2- lost an electron to become oxidized. According to the current signal produced by electron transfer, NO2- could be quantitatively detected. The modified Cu-MOFs could catalyze the oxidation of NO2-, thereby contributing to increased response signal from the working electrode and improving the sensitivity of NO2- detection. NO2- concentration was measured by differential pulse voltammetry using Cu-MOFs/GCE. The peak current increased linearly with the NO2- concentration in the range of 10–1 200 μmol/L. The limit of detection was 1.57 μmol/L. Besides, the prepared electrochemical sensor exhibited good selectivity and stability. The results of the sensor for the nitrite content in meat products were in good agreement with those obtained by the naphthyl ethylenediamine dihydrochloride spectrophotometric method, indicating that the electrode has great potential in the analysis of nitrite in food samples.

Key words: nitrite; meat products; metal organic framework; differential pulse voltammetry; electrochemical sensor