Cu-BTC frameworks-based electrochemical sensing platform for rapid and simple determination of Sunset yellow and Tartrazine

It is quite important to develop simple and rapid analytical methods for Sunset yellow and Tartrazine due to their high toxicity and widespread use. Using 1,3,5-benzenetricarboxylate ion (BTC3-) as the ligand and copper ions as the center, Cu-BTC frameworks with high electrochemical activity were prepared, and used to construct a novel detection platform for Sunset yellow and Tartrazine. On the surface of Cu-BTC frameworks, their oxidation signals increase greatly. The signal enhancement mechanism was studied using electrochemical impedance spectroscopy and chronocoulometry. It is found that the prepared Cu-BTC frameworks remarkably enhance the electron transfer ability and accumulation efficiency of Sunset yellow and Tartrazine. The influences of pH values, modification amount of Cu-BTC, accumulation potential and time were investigated, and a highly -sensitive electrochemical sensing system was developed. The linear range is from 0.3 to 50 nM for Sunset yellow, and from 1.0 to 100 nM for Tartrazine. The values of detection limit are evaluated to be 0.05 and 0.14 nM for Sunset yellow and Tartrazine. The sensing platform was used to determine the contents of Sunset yellow and Tartrazine in different drink samples. The results consist with the values that obtained by high-performance liquid chromatography. (C) 2016 Elsevier B.V. All rights reserved.