Portable Electrochemical Sensor Using PtCu/Mo2C for the Determination of NO2− in Food Samples

Nitrite (NO2−), a widely used food additive, may pose health risks when consumed in excess, making the development of highly sensitive, rapid, and portable detection methods of great importance. Electrochemical methods have been widely applied to NO2−detection because of their simplicity, low cost, and fast response. In this work, based upon a portable potentiostat (xenSTAT), a NO2−electrochemical sensor has been successfully developed and combined with the modification of PtCu nanospheres on flower-like Mo2C (denoted as PtCu/Mo2C) on screen-printed electrodes (SPEs). Owing to the excellent electrochemical activity and catalytic capability of PtCu/Mo2C, the proposed electrochemical sensor exhibited a wide linear range (10–1000 µM), high sensitivity (0.0229 µA µM−1) and a low detection limit (0.98 µM). Moreover, the sensor was successfully applied for detecting nitrites in sausages and milk, showing also good recovery.