Non-enzymatic electrochemical sensor based on an AuNPs/Cu-N-C composite for efficient nitrite sensing in sausage samples

Abstract

Nitrogen-doped carbon materials have attracted enormous attention in the field of detection due to their high catalytic activity. Herein, Cu-N-C materials were synthesized by the template method and used to construct a non-enzymatic electrochemical sensor combined with gold nanoparticles (AuNPs) for nitrite detection. The prepared AuNPs/Cu-N-C modified glassy carbon electrode (GCE) exhibited excellent electrocatalytic oxidation performance, and the oxidation peak potential was reduced to 0.75 V. The synergy of the AuNPs and Cu-N-C material greatly improved the charge conduction pathways between the electrode and nitrite and accelerated the charge transfer rate, resulting in the enhancement of the catalytic performance of the as-developed sensor. Under optimized conditions, the constructed electrochemical sensor platform exhibited a wide linear range of 1 μM–1 mM and 1 mM–10 mM, and a corresponding low detection limit of 0.01 μM. In addition, the sensor exhibited superior selectivity and reproducibility. It was successfully applied for nitrite determination in sausage samples. This study not only provides an innovative strategy to design a highly sensitive electrochemical sensor but also broadens the application of Cu-N-C materials in the field of food safety.