Determination of Sunset Yellow in Foodstuffs by Surface Modification of Nonconductive Polyester of Polyvinyl Alcohol Sheet Used as Overhead Projector Film

Abstract

In this research, a new strip electrode was demonstrated for sunset yellow (SY) detection. This electrode was prepared by surface modification of nonconductive polyester of polyvinyl alcohol sheet used as overhead projector film with a layer of 3-mercaptopropyltrimethoxysilane, silver nanoparticles, and poly tartrazine/graphene oxide nanocomposite film, essentially to bring in the conductivity and catalytic activity towards SY detection. Large specific surface area and high conductivity of the proposed electrode made it an excellent sensing platform for sensitive determination of SY. The experimental parameters such as supporting electrolyte and its pH, the number of cycles for the electropolymerization, and the scan rate for the sensor preparation were optimized. Under the optimum operating conditions, the peak currents for SY were found to vary linearly with its concentrations in the wide range of 0.003–0.9 and 0.9–10.0 μmol/L. The estimated detection limit and sensitivity of the proposed electrode were 0.001 μmol/L and 8.40 μA L/μmol, respectively. This sensor could be successfully applied for the determination of SY in food samples. It is worth noting that the modified polyester strip by silver film and the nanocomposite of poly tartrazine/graphene oxide was first used in this study as an electrode.