A colorimetric and near-infrared ratiometric fluorescent probe for hydrazine detection and bioimaging

Hydrazine (N₂H₄) is extensively used in industry but highly toxic; hence, highly sensitive detection of N₂H₄ is extremely meaningful. Herein, a colorimetric and near-infrared (NIR) ratiometric fluorescent probe named DXM-OH was rationally designed and synthesized based on oxanthrene malononitrile derivative for the specific detection of N₂H₄. The dicyanovinyl group in DXM-OH was served as the recognition unit for N₂H₄. DXM-OH showed high sensitivity to N₂H₄ in the range of 1-900 μM, with the limit of detection (LOD) of 0.09 μM (2.87 ppb), which is much lower than the U.S. Environmental Protection Agency standard (10 ppb). Furthermore, the practical applications of DXM-OH in detecting N₂H₄ in real water samples and imaging of N₂H₄ in living cells were demonstrated, indicating its potential utility for N₂H₄ sensing in environmental and biological samples.