Reza Hajian - Department of Chemistry, Islamic Azad University, Gachsaran Branch, Gachsaran, Iran
Saiedeh Azhdari - Department of Chemistry, Islamic Azad University, Gachsaran Branch, Gachsaran, Iran

Food coloring, or color additive, is any dye, pigment or substance that imparts color when it is added to food or drink. Food coloring is used both in commercial food production, domestic,pharmaceuticals and medical devices [1]. Food dyes were originally synthesized from coal tar, but now they are synthesized from petroleum. These dyes are used because they are cheaper and brighter than most natural food colorings. Food dyes are not pure chemicals, they can contain upto 10% of impurities that are in chemicals from which dyes are made or developed in the manufacturing process. Sunset Yellow (SY) is a petroleum-derived orange azo dye used in food, cosmetics, and drugs. [2-3] For example, it is used in candy, desserts, snacks, sauces, and preserved fruits. Sunset Yellow is often used in conjunction with E123, amaranth, to produce abrown coloring in both chocolates and caramel. Graphene nanoplatelets (GNPs) represent a new class of carbon nanoparticles with multifunctional properties. Each particle consists of several sheets of graphene with an overall thickness of about 5 to 25 nm. This unique size and platelet morphology makes these particlesespecially effective at providing barrier properties, while their pure graphitic composition makes them excellent electrical and thermal conductors. Their thermal conductivity and mechanical properties are similar to carbon nanotubes (CNTs) but their aspect ratios are higher than CNTs.GNPs have been thus widely applied as the electrode materials in many fields [4,5], e.g. for sensing applications, loading catalysts and constructing batteries and supercapacitors.In this study, a highly sensitive electrochemical sensor for the determination of sunset yellow asa food coloring was fabricated using graphene nanoplatelets modified platinum electrode. Cyclic voltammetry studies shows that the modified electrode has higher sensitivity for oxidation/reduction of SY with a pair of well peaks at 0.708 and 0.625 V (versus Ag/AgCl) in Britton Robinson buffer (pH 3.0, 0.1 M). Some parameters such as kind of supporting electrolyte, pH, volume of coated graphene nanoplatelets and scan rate have been optimized to get higher sensitivity. The fabricated electrochemical sensor can be successfully applied to the determination of SY as a coloring additive in drinks and foods

Graphene nanoplatelets, Platinum electrode, electrochemical sensor, Sunset Yellow