A new electrochemical sensor based on MXene/helical carbon nanotube/bimetallic FeCo-MOF composite for highly sensitive nitrite detection in food samples

Bimetallic MOF materials (FeCo-MOF) were prepared with a simple hydrothermal method. • MXene/HCNTs and FeCo-MOF have synergistic effects on electrocatalytic NO 2 − oxidation. • This sensor exhibits low detection limit (0.154 μM) and wide linear range for NO 2 − . • MXene/HCNTs/FeCo-MOF/GCE has excellent selectivity, reproducibility and stability. • Successfully applied to analyze NO 2 − in foods (milk, sausage, and bottled water). Nitrite is a common food additive, however, studies have shown that long-term intake of large amounts of nitrite can pose significant health hazards to humans, so the accurate determination of nitrite content in food is of great importance. In this paper, an electrochemical sensor exhibiting remarkable sensitivity and selectivity for NO 2 − detection was successfully constructed using a composite material (MXene/HCNTs/FeCo-MOF), using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS) to characterize the MXene/HCNTs/FeCo-MOF, and investigating the electrocatalytic performance of MXene/HCNTs/FeCo-MOF-modified electrode for NO 2 − by cyclic voltammetry (CV) and differential pulse voltammetry (DPV), the results revealed MXene/HCNTs/FeCo-MOF/GCE exhibited both an extensive linear range (0.5–300 μM) and a minimal detection limit (0.154 μM). Meanwhile, the modified electrode was also successfully realized for detecting NO 2 − in food (milk, sausage and bottled water), which has potential applications. Download: Download high-res image (101KB) Download: Download full-size image