Quasi-ZIF-67 for high sensitivity electrochemical nitrite detection

Abstract

The partial deligandation of ZIF-67 was prepared via the calcination under a nitrogen atmosphere to obtain Quasi-ZIF-67. The calcination temperature and calcination time were systematically investigated. The material calcinated at 350 °C for 2 h retained a relatively complete framework with high porosity while removing the partial organic ligands, exposing numerous metal active sites. The novel electrochemical sensing platform based on Quasi-ZIF-67-350-2 was applied for nitrite detection by amperometry methods in 0.1 M PBS (pH 7.0). With the numerous metal active sites, superior electronic conductivity and high porosity of Quasi-ZIF-67-350-2, the modified electrode exhibited a high sensitivity of 122.3 μA mM⁻¹ cm⁻² and a wide linear range (0–83.0 mM) for nitrite detection. What’s more, the novel nitrite sensor demonstrated a promising application prospect in sausage samples.