A flavonol-derived fluorescent probe for highly specific and sensitive detection of hydrazine in actual environmental samples and living zebrafish

Hydrazine (N2H4) is a significant chemical reagent and widely applied in industrial field, which can bring potential risk to environmental safety and human health due to its high toxicity and potential carcinogenicity. In this paper, a flavonol-derived fluorescent probe named TB-N2H4 was rationally developed for detecting N2H4 based on the excited intramolecular proton transfer (ESIPT) principle. TB-N2H4 exhibited a remarkable fluorescence turn-on response toward N2H4 with a large Stokes shift of 191 nm. Moreover, TB-N2H4 could selectively recognize N2H4 over other competitive analytes, and displayed high sensitivity toward N2H4 with a low detection limit of 0.117 μM. The sensing mechanism of the probe TB-N2H4 for N2H4 was confirmed by theoretical calculation and HRMS analysis. This probe was able to quantitatively determine N2H4 in environmental water and soil samples. Additionally, TB-N2H4 was also successfully utilized for real-time tracking of the distribution of N2H4 in living zebrafish.