A sensitive TICT Probe exhibiting ratiometric fluorescence repose to detect hydrazine in solution and gas phase

A twisted intramolecular charge transfer (TICT) based probe, dicyanovinyl-9-phenylanthracene (DPA) has been designed and synthesized for the detection of hydrazine (N2H4) with good limit of detection (LOD, 7.85 nM (0.25 ppb)). Upon interaction with hydrazine the terminal electron withdrawing dicyanovinyl function is changed to electron donating amino/hydrazone function. Consequently, the significant change in the photophysical property of the probe is attributed to a change in orientation of charge propagation. The probe with hydrazine shows ratiometric fluorescence "turn-on" response as well as naked-eye sensitive color change in the medium. The surface morphology studies (SEM and TEM) suggested about amorphousness and crystalline nature of the probe DPA and derivative DPA-HDz, respectively. The conducting behavior of the probe decreases upon interaction with hydrazine because of decrease in amorphousness of the matrix and increase in relatively more rigid crystalline structure. Additionally, the probe been utilized to detect hydrazine vapor in solution and on test paper strip with good naked-eye sensitive responses.