Reversible Emitting Anti-Counterfeiting Ink Prepared by Anthraquinone-Modified β-Cyclodextrin Supramolecular Polymer

Intelligent fluorescent materials have been paid more and more attention due to their wide application in information encryption and anti-counterfeiting materials. Herein, a supramolecular polymer is constructed through the host-guest interaction of anthraquinone-modified β-cyclodextrin (AQ-β-CD) in aqueous solution. Thanks to the hydrophobic microenvironment of the cyclodextrin cavity and the shielding effect on oxygen molecules, the anthraquinone group, as the guest molecule, can rapidly produce 9,10-anthracenediol (QH₂) with strong fluorescence by photoreduction. Interestingly, the generated anthracenediol group is still sensitive to oxygen and can be converted to anthraquinone by oxygen. Significantly, aqueous solution of AQ-β-CD supermolecular polymer is used as emitting ink, which decrypts the information by ultraviolet light and encrypts the information in the air.

Keywords: anthraquinone photoreduction; cyclodextrin; fluorescent anti‐counterfeiting; fluorescent encryption; supramolecular assembly.