An ultra-sensitive electrochemical sensing platform based on nanoflower-like Au/ZnO array on carbon cloth for the rapid detection of the nitrite residues in food samples

In this work, we constructed an enhanced electrochemical signal sensing platform using Au/ZnO nanoflake arrays coated on carbon cloth for the rapid detection of nitrite in food. Based on a stepwise synthesis strategy of electrodeposition and magnetron sputtering technique, AuNPs were sputtered onto ZnO nanoflower-like array sheets. Combining the high catalytic performance of AuNPs with the morphology of ZnO significantly increased the surface area and electrocatalytic activity of the electrodes. The prepared sensor showed a linear response range of 0.2-4986 μΜ, a limit of detection of 0.09 μM, and a high sensitivity of 5677 μA mM-1 cm-2. It is worth noting that the sensor can precisely detect nitrite in the presence of interfering substances and has excellent stability and reproducibility. In addition, the nitrite residues in several food samples were analyzed using this method and spectrophotometric method, and the results of the two methods were not significantly different.