Highly sensitive electrochemical sensor for sunset yellow based on the enhancement effect of alumina microfibers

It is quite important to monitor synthetic dyes in foods because of their potential harmfulness to human beings. Herein, alumina microfibers with porous structures were prepared via hydrothermal reaction, and then used to construct a highly sensitive platform for the detection of sunset yellow. In pH 6.5 phosphate buffer, an oxidation peak was observed for sunset yellow, and the oxidation peak currents of sunset yellow were greatly increased by alumina microfibers. The influences of pH value, amount of alumina microfibers and accumulation time on the signal enhancement of sunset yellow were discussed. As a result, a novel electrochemical method was developed for the detection of sunset yellow. The linear range was from 0.5 to 100 nM, and the limit of detection was 0.16 nM (72.4 ng L−1) after 2-min accumulation. It was applied in soft drink samples, and the detected results consisted with the values that obtained by high-performance liquid chromatography.