Rhodol assisted alternating copolymer based chromogenic vesicles for the aqueous detection and quantification of hydrazine via switch-on strategy

Hydrazine, a highly toxic pollutant in combination with its environmental impacts, posing a severe threat to the human health. These detrimental effects guarantee the designing of sensitive and selective approaches for the recognition of hydrazine. In this regard, the fluorometric and colorimetric approaches grasped distinctive attention of the researchers due to their sensitive, selective and biologically compatible nature. Selective detection of hydrazine is always more thought provoking in comparison with the detection of metal ions. This limitation owes to the strong H-bonding ability and restricted modes of reaction by hydrazine with most of the solvents. Here, we develop an alternating copolymer based vesicle sensor polyethylene glycol diglycidyle ether-alt-dimercaptosuccinic acid grafted with Rhodol (PEGDG-a-DMSA-g-RL) for the selective, sensitive and visual detection of hydrazine. The newly engineered vesicle sensor utilizes the self-assembling behavior of PEGDG-a-DMSA-g-RL followed by the strong coordination of the lone pairs present at nitrogen atom of hydrazine with electropositive carbonyl carbon atom of RL. This interaction leads to the deprotection of the fluorophore molecule attached on the surface of the polymeric vesicles. This deprotection result in the significant enhancement of spectral behavior (fluorescence and UV–Visible) of the sensor. Subsequently, this deprotection leads to the colorimetric transition of solution from colorless to pink color (visible to naked eye). This colorimetric transition evidence the visual recognition of hydrazine for in-field mapping with ease. Furthermore, the lowest limit of detection was calculated as 3.0 nM. Finally, the aqueous quantification of hydrazine was carried out by using the distilled and raw water samples. The results obtained shows that the vesicle sensor have excellent quantification ability in terms of percentage recovery of hydrazine not <96%.