Morphology control of ZnO by adjusting the solvent and non-enzymatic nitrite ions electrochemical sensor constructed with stir bar-shaped ZnO/ Nafion nanocomposite

Excessive uptake of food or drinking water which is rich in nitrite has been demonstrated to be very hazardous to both the health of humans and animals, so it is of great significance to develop a reliable technique for lowconcentration detection of nitrite. Herein, we reported the synthesized zinc oxide which is an excellent electrochemical material for the sensing of nitrite. Interestingly, the ZnO material exhibits a strong dependent relationship between the electrochemical sensing performance and its morphology controlled by the solvent employed in the solvo-thermal method. In particular, the stir-bar shaped ZnO nanorods, with a 40-90 nm width and 50-170 nm length, display significantly improved electrocatalytic performance to the electrochemical oxidation of nitrite which is benefited from the more reactive active sites based on the higher dispersion and smaller size. The sensor based on ZnO/Nafion modified glassy carbon electrode (ZnO/Nafion/GCE) shows a broad linear response within the range of 0.3 mu M-6.14 mM and 0.8 mu M-4.86 mM, respectively, for amperometry and linear sweep voltammetry (LSV), the corresponding limit of detection (LOD) were calculated to be 0.21 mu M and 0.62 mu M, respectively. Also the prepared sensor shows excellent sensitivity, reproducibility, stability and high anti-interference abilities. More importantly, the satisfactory recovery is obtained from ham sausage, pickle and running water, demonstrating the great application prospects of this sensor. In addition, the sensing mechanism of such ZnO sensing to nitrite is also discussed in detail.

Automated summary

In this work, synthesized zinc oxide has been reported as an excellent electrochemical material for sensing nitrite, particularly the stir-bar shaped ZnO nanorods show significantly improved electrocatalytic performance. The sensor based on ZnO/Nafion modified electrode exhibits a broad linear response range, good sensitivity, stability, and anti-interference abilities. Additionally, satisfactory recovery from food and water samples demonstrates the great application prospects of this sensor.