writer：Xiaoxia Le, Hui Shang, Huizhen Yan, Jiawei Zhang,* Wei Lu, Mingjie Liu,* and Tao Chen*
keywords：hydrogel, multistage information security protection
source：期刊
specific source：Angew. Chem. Int. Ed., 2021, 60, 3640-3646
Issue time：2021年

The improper handling of decrypted information will lead to the second leakage of confidential data. Thus, there is an ever-increasing interest yet grand challenge in developing a new strategy of self-erasing decrypted data. Here we address this challenge by designing urease catalysis in hydrogel with spatiotemporal regulation for multistage information security protection. We fabricated fluorescent hydrogel based on the protonated 4-(N,N-dimethylaminoethylene) amino-N-allyl-1,8-naphthalimide (DEAN-H+), doping with urease as a urea responsive catalysis system that can produce NH3 in spatiotemporal regulation with a subsequent fluorescence weakness due to the photoinduced electron transfer (PET) effect triggered by the deprotonation of naphthalimide moieties. Upon the information input using metal ions such as Zn2+ that can coordinate with DEAN in hydrogel to maintain the fluorescence properties, which could be slowly weakened by the urease catalysis compared with the fast weak process of DEAN-H+ hydrogel in urea solution. Therefore, taking advantage of time variety, encrypted information on the hydrogel could be decrypted in urea solution, and the displayed information could be automatically erased within a few minutes on the basis of the step wisely fluorescence off behavior. This work opens up a new insights in designing and fabricating information storage materials for Snapchat (disappear after reading) to against rising problems in counterfeiting.