CeO2/MWCNT/Carbon Black Modified Electrode for Improving the Performance of Electrochemical Nitrite Sensor

Abstract CeO2 was synthesized and combined with different types of carbon nanomaterials such as carboxylated multiwalled carbon nanotubes (c-MWCNT) and carbon black (CB) for electrochemical detection of nitrite. The composite (c-MWCNT/CB/CeO2) showed the best sensing performance. It was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscpy, Brunnauer-Emmett-Teller, and Raman spectroscopy. The electrochemical performance of the c-MWCNT/CB/CeO2 modified fluorine-doped tin oxide (FTO) glass and glassy carbon electrode (GCE) was studied. The optimized c-MWCNT/CB/CeO2/FTO sensor exhibited a linear range of 0.01-13 mM, a sensitivity of 231.4 μA·mM-1·cm-2, and a detection limit of 0.59 μM, while the c-MWCNT/CB/CeO2/GCE sensor showed a linear range of 0.01-33 mM, a sensitivity of 340.5 μA·mM-1·cm-2, and a detection limit of 0.45 μM. In addition, the sensor had good stability, reproducibility and selectivity. More importantly, it was successfully used for nitrite detection in green tea samples, indicating its feasibility.