An effective benzothiazole-indandione D-π-A fluorescent sensor for "ratiometric" detection of hydrazine: Its solvatochromism properties and applications in environmental samples and living cells.

Hydrazine (NH) has high toxic impact and is widely used as raw material. As a result, it poses serious health risks and the following environmental pollution. Therefore, hydrazine's detecting techniques remains constantly under investigation. Herein, we report a ratiometric D-π-A fluorescent probe displaying NIR emission based on the ICT mechanism to detect NH. Other tested analytes have no observable interferences on the sensitivity and selectivity. The probe has sensitivity for NH down to 1.29 μM with quick detection time (about 2.0 min). Moreover, the probe demonstrates solvatochromism with obvious emission varying from dull red to green, which implied high sensitivity to medium polarity. A portable smartphone platform for point-of-care detection of NH in water samples is constructed. As a proof of real samples, the probe is successfully applied to sense NH in water samples, to bioimage NH in living cells and in plant cells with low cytotoxicity, suggesting significant potential application. This strategy opens up the preparation of new ratiometric fluorescence systems for bioimaging and environmental monitoring applications.