Facile synthesis of Fe-BTC and electrochemical enhancement effect for sunset yellow determination

Sunset yellow is a widespread man-made azo dye in foods, which can adversely affect humans. It is an important mission to research simple and sensitive determination method. This work reports a new electrochemical method for the determination of sunset yellow based on the ambient fast synthesized Fe-BTC. Using Fe-BTC frameworks as sensing materials, modified carbon paste electrode was prepared (Fe-BTC/CPE). Its electrochemical properties were explored by using redox probes and sunset yellow. The results showed that Fe-BTC/CPE possessed larger electrochemical active area, faster electron transfer capacity, and higher accumulation efficiency, therefore resulted in enhanced oxidation signal. On account of the excellent enhancement effect of Fe-BTC frameworks, a simple sunset yellow electrochemical determination method was developed. The linear range is from 0.1 to 50 nM, and the detection limit is 0.015 nM. This new method was successfully applied for the determination of sunset yellow in drink samples, and the results in accord with the dates got by HPLC, which may hold great potential for the in-field food safety monitoring.