High-performance nitrite sensing using ternary PANI/SnO₂/MoS₂ nanocomposites with enhanced electrochemical response

Nitrite contamination poses a significant hazard to environmental safety and human health, making it essential to develop highly sensitive and selective detection methods. In this study, a ternary polyaniline/tin dioxide/molybdenum disulfide (PANI/SnO 2 /MoS 2 ) nanocomposite was designed and synthesized for high-performance electrochemical nitrite sensing. The nanocomposite was thoroughly characterized using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). A glassy carbon electrode (GCE) modified with this nanocomposite was constructed as an electrochemical sensing platform for nitrite detection. The resulting sensor exhibited an electroactive surface area of 0.1344 cm 2 , which is 2.8 times that of the bare GCE. Owing to the synergistic effects among the three components, the sensor demonstrated excellent electrocatalytic activity towards nitrite oxidation. Under optimal conditions, it achieved a wide linear detection range from 0.9 μM to 1300 μM, with a sensitivity of 0.5606 μA · μM −1 · cm −2 , a detection limit of 0.33 μM (S/N = 3), and a quantification limit of 0.9 μM. The sensor also displayed outstanding selectivity, stability, and repeatability. Furthermore, it was successfully applied to detect nitrite in tap water samples, yielding satisfactory recovery rates.