[Chinese Chemical Letters] Excitation-wavelength-dependent fluorescent organohydrogel for dynamic information anti-counterfeiting
writer：Dong Guo, Xiaoxia Le*, Hui Shang , Fuqing Shan, Danyang Li, Chunfa Ouyang*, Tao Chen*
keywords：Fluorescent organohydrogel Anti-counterfeiting Stimulu s responsive Encryption-decryption Dynamic fluorescence
source：期刊
specific source：Chinese Chemical Letters, 2023, inpress
Issue time：2023年
Anti-counterfeiting labels with various fluorescent colors are of great importance in information encryption-decryption, but are still limited to static information display. Therefore, it is urgent to develop new materials and encryption-decryption logic for improving the security level of secret information. In this study, an organohydrogel made up of poly(N,N-dimethylacrylamide) (pDMA) hydrogel network and polyoctadecyl methacrylate p(SMA) organogel network that copolymerized with two fluorophores, 6-acrylamidopicolinic acid moieties (6APA, fluorescent ligand) and spiropyran units (SPMA, photochromic monomer), was prepared by a two-step interpenetrating method. As UV light of 365 nm and 254 nm can both cleave Cspiro-O bonds of SPMA, and the green fluorescence of 6APA-Tb3+ can only be excited by 254 nm light, the organohydrogel displays yellow and red under the irradiation of 254 nm and 365 nm, respectively. In addition to wavelength selectivity, these two fluorophores are thermal responsive, leading to the fluorescence variation of the organohydrogel during heating process. As a result, secret information loaded on the organohydrogel can be decrypted by the irradiation of UV light, and the authenticity of the information can be further identified by thermal stimulation. Our fluorescent organohydrogel can act as an effective anti-counterfeiting label to improve the information security and protect the information from being cracked.