Naphthalimide Based Optical Probe for the Detection of Hydrazine in Water and Their Application in Test Strips and...

A newly synthesized naphthalimide-based fluorophore probe NIA was used to detect hydrazine. This probe, based on the Gabriel mechanism exhibited a highly sensitive revealing of hydrazine in naked eyes colorimetric as well as fluorescent recognition against other amines in an aqueous solution in DMSO - HEPES buffer. When hydrazine hydrate was added to the probe NIA, the absorption was red shifted from 403 nm to 520 nm. The titration studies by adding hydrazine to show two apparent isosbestic points found at 358 and 450 nm, respectively. Further, investigation of emission spectra upon addition of hydrazine hydride the emission peak at 493 nm gradually decreased up to 2.4 equiv. and when increasing the hydrazine hydride concentration from 2.4 equiv. to 4.4 equiv., the fluorescence intensity increased at 530 nm. which is exhibiting a raised ratiometric emission intensity at 530 nm. Further investigation of the selectivity of probe NIA revealed colorimetric and fluorimetric responses to interferences with other test amines. ¹H NMR and HR-mass proved the Gabriel mechanism bath for detecting hazardous hydrazine by probe NIA. This probe NIA allowed the rapid and ultrasensitive detection of hydrazine hydride with a low detection limit of 0.26 nM. In view of the outstanding properties, probe NIA has been effectively performed to detect hydrazine using various techniques, including a test kit, silica support, and actual environmental water samples.