Aliphatic amines – Sensing application in aqueous media using supramolecularly stacked acriflavine dye on graphene oxide

Supramolecularly stacked acriflavine dye on graphene oxide (GO-Acy) was utilized for the first time to detect aliphatic amines, making it a highly sensitive and selective material. This method involved developing a distinctive, discriminative, and highly selective fluorescent sensor that displayed a ’turn-on’ response to aliphatic amines. The sensor probe operated through supramolecular host–guest interactions between the amines and dyes, enabling the detection of aliphatic amines. Upon the interaction of aliphatic amines with bound Acy dye on graphene oxide, the fluorescent sensor exhibited a release of Acy dyes and a rapid appearance of fluorescence. GO-Acy demonstrated high selectivity for 1,4-butanediamine (BD), exhibiting strong fluorescence intensity and accurately distinguishing it from various aliphatic amines, aromatic amines, and amino acids. The fluorescene emission intensities of GO-Acy at λ_em = 510 nm was observed after exposure to different amines, with an excitation wavelength of GO-Acy at λ_ex = 450 nm. In addition to its high selectivity, the sensor probe also exhibited excellent sensitivity towards BD, with a limit of detection (LOD) of 9.9 nM. This graphene-based material proved to be a highly effective tool for detecting aliphatic amines in aqueous media, requiring no special experiments while providing both good selectivity and sensitivity. Additionally, GO-Acy@CB[7] demonstrated diverse responses to aliphatic amines, suggesting its ability to discriminate between them through fluorescence quenching. GO-Acy has proven effective in monitoring fish products that release amine vapors during decomposition. Furthermore, test paper strips made with GO-Acy could quickly detect amines in actual fish samples, highlighting the potential of GO-Acy for food quality inspection.