Designation Graphene Oxide / Zinc Oxide and Palladium nanocomposite electrode to detect nitrite in Potato

Abstract

Abstract Introduction and goal: Considering the role of nitrites and nitrates in causing chronic diseases such as cancer and the high sensitivity of relevant organizations in determining the amounts of these compounds in food sources, identification, and rapid, accurate, and economical determination of their amounts have been considered in recent years. Among the various methods of measuring nitrite in food, electrochemical methods have attracted the attention of researchers due to their cheapness, high sensitivity, fast response time, and no need for a trained operator. In this regard, this study was designed to develop electrochemical sensors modified with graphene oxide/zinc oxide/palladium nanocomposite to measure nitrite ions in potato food samples. Materials and methods: To evaluate the amount of nitrite, an electrode based on graphene oxide/zinc oxide/palladium nanocomposite was designed. For this purpose, first, the synthesized graphene oxide/zinc oxide/palladium nanocomposite and the structural properties of the nanocomposite were evaluated using TEM, XRD, FE-SEM-EDS, FTIR images, and after confirmation, they were placed on the considered carbon electrode. The electrocatalytic behavior of the modified electrode towards the oxidation of nitrite ion in the potato sample was evaluated using the voltammetric method and the results were recorded by GPES software. Then, the necessary assessments were performed to achieve the optimal conditions for electrochemical experiments; and after that, the characteristics, sensitivity level, and detection limit of the designed electrode for measuring the nitrite amount in the potato food sample were investigated. Results: The internal structure and morphology characteristics of the synthesized nanocomposite surface were confirmed by TEM, XRD, FE-SEM-EDS, FTIR images. The results obtained from the assessment of the electrochemical behavior of the electrode showed that the application of the modified electrode with graphene oxide/zinc oxide/palladium nanocomposite resulted in the best response at a concentration of 12 μM and pH=6. The nature of the current on the modified electrode surface was diffusion-type and its sensitivity in detecting nitrite in the presence of glucose, potassium nitrate, and sodium sulfate was acceptable and no interference was observed in the electrochemical results. Conclusion: The graphene oxide/zinc oxide/palladium nanocomposite has high sensitivity and accuracy in measuring the nitrite ion of vegetables compared to the spectrophotometric method and can be introduced as an alternative method. Keywords: Graphene oxide, Zinc oxide, Palladium, Nitrite