Efficient electrochemical determination of Sudan I in food samples based on modified electrode by using Ni-Fe layered double hydroxide nanosheets and ionic liquid

Sudan I, is one of the commonly used azo dyes in food samples, which has shown adverse effects on human health. Therefore, determining the level of Sudan I in food samples can be very effective in ensuring food safety and protecting human health. In this study, an electrochemical sensing platform was designed using Ni-Fe layered double hydroxide nanosheets and ionic liquid modified carbon paste electrode (Ni-Fe LDH/ILCPE) which was utilized to determine Sudan I. Comparison of cyclic voltammograms of Sudan I on the unmodified CPE and Ni-Fe LDH/ILCPE showed that, the higher oxidation currents were obtained on the surface of the Ni-Fe LDH/ILCPE, indicating that the modified CPE owns significant surface improvement effects and good electrochemical performance in detecting Sudan I. Under optimized conditions, the developed Ni-Fe LDH/ILCPE sensor demonstrated a linear relationship between the voltammetric response and Sudan I concentrations from 0.03 µM to 510.0 µM with a low detection limit (LOD) of 0.01 µM based on S/N = 3.0. Additionally, the Ni-Fe LDH/ILCPE platform exhibits high accuracy, with a recovery of 96.4 % to 104.1 % for Sudan I determination in food samples including Ketchup and Chilli powder, which implies that it will be a potential detection method for Sudan I detection.