Determination of carmoisine in food samples using nanostructure based electrochemical sensor

Carmoisine is a synthetic azo food dye in the red to maroon colour range. In the US, this color was listed in 1939 as D C Red No. 10 for use in externally applied drugs and cosmetics. It was delisted in 1963 because no party was interested in supporting the studies needed to establish safety. It was never used in food in the US [1]. In this work, we describe synthesis of NiO/CNTs nanocomposite by chemical precipitation method. The synthesized nanocomposite identified by XRD, SEM, and TEM methods. In continuous, a carbon paste electrode modified with NiO/CNTs nanocomposite and ionic liquid (NiO/CNTs/IL/CPE) had been fabricated as a voltammeric sensor for determination of carmoisine. Electrochemical behavior of carmoisine at the NiO/CNTs/IL/CPE had been investigated in phosphate buffer solution (PBS) by cyclic voltammetry (CV), chronoamperometry (CA) and square wave voltammetry (SWV). The experimental results suggested that the modified electrode exhibited an electrocatalytic activity toward the redox of carmoisine. Detection limit of carmoisine was found to be 0.04 μM. The proposed sensor was successfully applied for the determination of carmoisine in food samples.