There is currently great interest in developing an environment-friendly, low-cost, and scalable approach for producing stimuli-responsive fluorescent hydrogels（FHs） with excellent mechanical property, rewritable fluorescence, and dual anti-counterfeiting capabilities. Herein, by applying natural, environment-friendly, and sustainable curcumin as a responsive agent, tough p H-responsive FHs（p H-FHs） are fabricated via a facile preparation strategy. These materials have outstanding mechanical performances: ultimate stress of 180 k Pa, an ultimate strain of ～2500%, and good anti-fatigue performances against compression. These p H-FHs are able to sense ammonia and formaldehyde gas, resulting in both a color change and fluorescence for dual anti-counterfeiting functionality. This sensing information is stored individually by the p H-FHs and could be externally removed using formaldehyde gas to achieve a rewritable system. Our study provides valuable insights that are expected to facilitate the development of smart FHs for information encryption and anti-counterfeiting applications.

Hydrogels have been widely used for various applications, and thus addressing the challenges associated with the design of sustainable hydrogels has become an important issue. However, little attention has been devoted toward the design of crosslinkers which are often toxic, lack self-healing capabilities, and derived from petrochemicals. Herein, novel cyclodextrin topological nanoparticles (TNPs) have been constructed. These TNPs were found to possess crosslinking capabilities and the corresponding TNPs-crosslinked hydrogels showed excellent mechanical performances with a high stretchability of 1860 % and stress of 180 kPa and good anti-fatigue abilities. These hydrogels could be readily recycled and used for modular assembly and disassembly in various shapes and could serve as flexible strain sensors to monitor human activities with a sensing range of 0-1800 %, controllable sensitivity, and good fatigue resistance. These topological nanoparticles can inspire the design of novel physical crosslinkers for novel flexible strain sensors, tough and self-healing hydrogels, and soft robotics.