Bifunctional fluorescent probe for detecting and imaging hydrazine hydrate both in vitro and in vivo

Hydrazine (N2H4), an important alkaline agent with reducing activity, is widely used in agriculture and chemical industry. Although N2H4 is not produced in the human body, inhalation of trace N2H4 from the environment can cause serious harm to organisms. Therefore, it is important to accurately detect trace N2H4 for ensuring safety. Compared with the traditional N2H4 probe, dual-channel detection can provide better imaging resolution. The design of conventional dual-channel probes is based on the excited-state intramolecular proton transfer (ESIPT), which is limited by the choice of matrix. Developing novel probe that does not depend on the ESIPT mechanism and can provide two-channel detection is needed. Herein, a novel bifunctional fluorescent probe PTFD was designed and synthesized. Compared with the monofunctional fluorescent probe PTD, PTFD can achieve dual-channel detected N2H4 with a rapid response, excellent selectivity, and high sensitivity (detection limit of 0.08 µM). Importantly, PTD and PTFD can be applied for imaging of N2H4 in HeLa cells and zebrafish because of their good optical properties and low toxicity.