A Novel Highly Sensitive Electrochemical Nitrite Sensor Based on a AuNPs/CS/Ti₃C₂ Nanocomposite

Nitrite is common inorganic poison, which widely exists in various water bodies and seriously endangers human health. Therefore, it is very necessary to develop a fast and online method for the detection of nitrite. In this paper, we prepared an electrochemical sensor for highly sensitive and selective detection of nitrite, based on AuNPs/CS/MXene nanocomposite. The characterization of the nanocomposite was demonstrated by scanning electron microscopy (SEM), a transmission electron microscope (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). Under the optimized conditions, the fabricated electrode showed good performance with the linear range of 0.5-335.5 μM and 335.5-3355 μM, the limit of detection is 69 nM, and the sensitivity is 517.8 and 403.2 μA mM^-1 cm^-2. The fabricated sensors also show good anti-interference ability, repeatability, and stability, and have the potential for application in real samples.