Construction of Bi-MOF/MXenes and their application in electrochemical nitrite sensors in food samples

In this work, a high-sensitivity electrochemical sensor was developed using a hybrid strategy, where sheet-like MXenes-based composites (Bi-MOF/MXenes) were prepared through the in-situ growth of bismuth-based metal-organic frameworks (Bi-MOF) on the MXenes surface. This hybrid composite material was fabricated using a simple physical synthesis method, which maintains excellent electrocatalytic activity while enhancing the electron transfer rate and electroactive surface area. The Bi-MOF/MXenes modified electrode has been demonstrated to be an effective tool for the detection of nitrite. The electrode exhibited a remarkable limit of detection (LOD) of 0.028   μM and a wide linear range of 0.5~4715   μM. The sensor exhibited remarkable repeatability and reproducibility, with relative standard deviation (RSD) values of 1.74% and 4.87%, respectively. The proposed approach was effectively utilized for detecting nitrite in sausage and fermented bean curd.