Conclusions

In conclusion, a simple and sensitive electrochemical sensor based on a SPCE with NiO nanostructures was successfully created. NiO nanostructures provide large surfaces, abundant active sites, and promote rapid electron transfer, resulting in excellent electrocatalytic activity for the oxidation of EP. Consequently, the EP sensor's performance evaluation demonstrated a LOD of 0.005 μmol L-1, a broad linear dynamic range from 0.01 to 400.0 μmol L-1, and high sensitivity. Well-defined, distinct oxidation peaks for EP and AC were obtained, enabling simultaneous detection and quantification of both substances using the NiO/SPCE platform. Finally, recovery rates between 96.7 and 103.4 % across all real-world samples validated the method's effectiveness for quantifying EP and AC in both urine and pharmaceutical products.