Dual Recognition Exhibiting a Polymeric Fluorescent Probe for Specific Detection and Removal of Hydrazine

Sensitive and specific detection of hydrazine (N 2 H 4 ) is of great importance for environmental ecology and human health due to its high biotoxicity. However, the selectivity of most existing N 2 H 4 probes relies on the reaction with one of the nucleophilic groups (−NH 2 ) of N 2 H 4, which cannot effectively discriminate N 2 H 4 from other amino compounds. Herein, we report a coumarin-appended polymeric probe (CFPF) for the selective detection and removal of N 2 H 4 in water solutions. By cross-linking aldehyde-coumarins with the acetylphenyl moieties on polystyrene, the polymeric multivalent probe was obtained, which endowed the polystyrene with excellent fluorophores and multiple electrophilic sites for special reaction with N 2 H 4 . In the presence of various competitive species, CFPF offers highly sensitive, specific, and rapid response to N 2 H 4 . The preliminary mechanism investigation revealed that the change in optical signal resulted from N 2 H 4 -mediated chalcone or chlorobuta-1,3-diene cyclization. The CFPF-based method for detecting N 2 H 4 gives a limit of detection (LOD) of 4.19 nM, which is lower than that suggested by USEPA (TLV, 10 ppb). Furthermore, a CFPF-loaded bead device was fabricated and used to monitor and extract N 2 H 4 in the wastewater samples. The reaction-specific and stable characteristics of CFPF-beads led to the extraction of trace N 2 H 4 from the water body. Overall, the proposed polymeric probe indicates its potential application for N 2 H 4 sensing and trapping in water samples and represents a prospective multivalent probe for practical applications.