The Detection of Food Additives Using a Fluorescence Indicator Based on 6– p–Toluidinylnaphthalence-2-sulfonate and Cationic Pillar[6]arene

Abstract

The current study investigated host-guest complexation in 6-p-toluidinylnaphthalene-2-sulfonate (TNS), a fluorescence probe used to investigate hydrophobic regions that contain the water-soluble cationic pillar[6]arene (CP6). After complexation with CP6, the fluorescence intensity of TNS was significantly increased. The decreases in the fluorescence intensity of the TNS•CP6 complex when phenolic food-additives are added have been used in indicator displacement assays to detect food additives in the water.

Recent advances in macrocyclic arenes-based fluorescent indicator displacement assays

“…Recently, the authors of this mini-review reported a novel fluorescence activation switch based on the host-guest complexation between a fluorescent indicator probe 6- p -toluidinylnaphthalene-2-sulfonate ( TNS ) and water-soluble pillar[6]arene dodecyl-ammonium chloride ( P6DAC ). The complexation remarkably increased the fluorescence intensity, and adding food additives (p-coumaric acid, trans-ferulic acid and gallic acid) to the TNS ⊂ P6DAC complex results in the displacement of TNS and thus causes a turn-off fluorescence response, which was employed for the F-IDA detection of phenolic food additives ( Duan et al, 2022 ).…”

Editorial: Host–guest chemistry of macrocycles— Volume II

“…However, the excessive use and accumulation of food additives in the environment is gradually increasing and is responsible for significant environmental concern. In this context, Duan et al prepared a novel FID assay based on a cationic PA[6] ( CP6 ) for the detection of some vital phenolic food additives, such as p -gallic acid ( GA ), trans-ferulic acid ( FA ) and coumaric acid ( CA ) ( Duan et al, 2022a ). The 6- p -toluidinylnaphthalene-2-sulfonate ( TNS ) was used as the fluorescent indicator in this FID system due to its enhanced emission in non-polar environments.…”