Detection of sunset yellow in food at biomediated Ag nanoparticle-based electrochemical sensor

Abstract Concerns regarding food safety emerge from the utilisation of synthetic colours such as sunset yellow (SSY). Utilisation of conventional methods is costly and labour-intensive, whereas electrochemical techniques are more efficient. Metallic nanomaterials such as gold, zinc, and silver are essential for the detection of synthetic dyes owing to their heightened sensitivity, simplicity, and real-time functionality. This research employs green synthesised silver nanoparticles (GAg NPs) derived from Vernonia amygdalina plants to construct an electrochemical sensor for the detection of SSY. Morphological analysis of the synthesised nanoparticle using scanning electron microscopy and transmission electron microscopy, reveals that the nanoparticles possess a spherical morphology, with an average particle size of 6.56 nm and show negligible aggregation. The UV–visible spectra exhibited a high absorption at 425 nm and a unique surface plasmon resonance absorption peak at 625 nm, indicating superior optical characteristics. The voltammogram of the modified electrode exhibited distinct oxidation and reduction peaks for the SSY analyte. The electrochemical sensing abilities of the modified gold-GAg NPs electrode were investigated. They demonstrated significant electrocatalytic activity in the detection of SSY, exhibiting a relatively low limit of detection of 1.3 × 10 −3 nM. The results from this study demonstrate the superior selectivity and stability of the proposed sensor. Consequently, the GAg NPs nanosensor is an advantageous candidate for an electroanalytical method employed in the identification of food additives.