Sub-micro electrochemical recognition of carmoisine, sunset yellow, and tartrazine in fruit juices using P(β-CD/Arg)/CysA-AuNPs/AuE.

An electrochemical sensor was designed to identify food colorants in juices. A green polymeric nanocomposite (beta-cyclodextrin/arginine) decorated with gold nanoparticles-capped cysteamine was fabricated on the surface of gold electrodes. Field emission-SEM and energy-dispersive X-ray spectroscopy showed the morphology and the presence of all elements related to all stages of the electrode modification. For three azo dyes (carmoisine, sunset yellow, and tartrazine), the analytical linear range was 10 to 10 M, with a low limit of quantification of about 1 nM. The engineered chemosensor showed suitable selectivity for analyzing candidate dyes in the presence of interfering agents. According to the scan rate results, the mass transport was controlled by diffusion, and the reaction on the chemosensor was electrochemically quasi-reversible. The results for different fruit juices confirmed this method's high potential application in detecting artificial color adulteration in food products.