An electrochemical sensor based on full-faradaic-active nitrogen species doped porous carbon materials for highly sensitive nitrite detection

Excessive nitrite (\(\:{\text{NO}}_{\text{2}}^{-}\)) addition poses a significant threat to food safety. Thus, it is desirable to construct a selective and dependable electrochemical sensor for the quantitative measurement of \(\:{\text{NO}}_{\text{2}}^{-}\). In this study, an electrochemical sensor using nitrogen-rich porous carbon (NPC) derived from graphitic carbon nitride (g-C₃N₄) was developed for the quantitative detection of \(\:{\text{NO}}_{\text{2}}^{-}\). The NPC synthesis involved a two-step process, namely polymerization and carbonization. The carefully designed polymerization method and optimal carbonization condition yielded an NPC material with a relatively high surface area of 593.36 m²·g⁻¹. Notably, NPC nanomaterials exhibited a high nitrogen content of 19.8%, comprising various nitrogen species (pyridinic N, pyrrolic N, and oxidized N) that are fully faradaic-active N species, leading to enhanced electrochemical properties and sensitivity. The calibration plot exhibited linearity within the concentration range of 2-3410 µM, LOD of 0.11 µM, a sensitivity of 11.32 µA·µM^− 1 cm^− 2 and further showed excellent adaptability in real sample analysis. This innovative way of creating electrochemical sensors from nitrogen-rich porous carbon materials broadens the scope of electroanalysis and provides a beneficial means of guaranteeing food safety.