Engineering a fluorescent probe for the visual and wearable detection of N2H4 in foods, environment samples and biological imaging

Hydrazine (N₂H₄), as an important chemical raw material widely used in many fields, caused serious harm to human, food and environment. Therefore, a smart fluorescent probe TPC-N₂H₄ with intramolecular charge transfer (ICT) process was fabricated for colorimetric and fluorescent differentiating of N₂H₄ in many samples. When TPC-N₂H₄ met N₂H₄, blue emission at 451 nm was obviously observed attributed to the interruption of ICT process, resulting in the formation of the hydrazone structure. Additionally, smartphone-assisted colorimetric and fluorescent sensing platforms had been developed for real-time monitoring of N₂H₄. Importantly, TPC-N₂H₄ with low toxicity revealed its ability to image N₂H₄ in HeLa cells, onion and Arabidopsis thaliana. Interestingly, a hydrogel-coated cotton swab sensor was developed with TPC-N₂H₄ as recognition unit, which showed obvious color and emission changes after N₂H₄ fumigation with fast response speed. Flexible fluorescent TPC-N₂H₄-glove was constructed for wearable N₂H₄ detection and used to monitor N₂H₄ in food and environment samples. In brief, the TPC-N₂H₄ probe not only showed great potential in N₂H₄ detection for environmental and food safety, but also provided a new method for wearable tracking platforms in toxic substance detection.