Fluorescent detection of tartrazine based on the supramolecular self-assembly of cationic perylene diimide.

A cationic perylene probe was designed and synthesized for sensitive determination of tartrazine. In the presence of tartrazine, the fluorescence of the perylene probe was quenched by efficient supramolecular self-assembly of the perylene derivate. The quenching is caused by the synergistic effect of noncovalent interactions including static electricity, π-π stacking, and hydrophobic interaction. Benefiting from these advantages, the probe exhibited excellent sensing performance to tartrazine within 2 min. The detection and quantification limit of tartrazine are as low as 2.42 and 8.07 nmol L^-1, respectively, with a wide linear operation range from 15 to 500 nmol L^-1. Most importantly, due to the high binding affinity (3.22 × 10⁷ mol L^-1) between the perylene probe and tartrazine, the sensing system shows great anti-interference capacity. Subsequently, the visualization application of the approach was evaluated by portable device, and the limits of detection for visual detection for test strip, membrane, and hydrogel were 0.5, 0.5, and 5 μmol L^-1, respectively. The approach has been applied to monitor tartrazine in various food condiments with recoveries in the range 91.29-108.83%. As far as we know, this is the first report of using perylene-based probe for tartrazine determination, offering a promising strategy for the construction of perylene-based detection system in the field of food safety.