Na-doped ZnO thin film by USP method for amperometric detection of Alura Red (E129) azo dye

Allura red (E129), which is in the azo dye class, is one of the synthetic dyes used in the food, cosmetic, and pharmaceutical industries. Given its growing industrial use and potential health risks, it’s important to determine its concentration at the lowest possible level. Therefore, in this study, experiments were conducted on the development of a platform for the electrochemical detection of AR with thin film layers of ZnO NPs deposited using the ultrasonic spray pyrolysis method on soda-lime glass substrates using the amperometric method based on the detection of resistance change. Undoped and Na⁺ ions (2% and 4%)-doped ZnO thin films were grown on soda-lime glass substrates at 400 °C using ultrasonic sputtering (USP). The characterization of the produced Na⁺@ZnO thin films was performed using various analysis methods, including XRD, FESEM, and EDS. The results showed that ZnO was homogeneously dispersed on the glass surface and positively affected the detection of azo dyes at low concentrations. The amperometric method determined the amount of AR azo dye in water. This research demonstrates that a well-designed hierarchical structure in the new Na⁺@ZnO electrocatalyst can successfully detect azo dye at concentrations as low as 0.01 ppb.