Highly Selective Sub-ppm Naked-Eye Detection of Hydrazine with Conjugated-1,3-Diketo Probes: Imaging Hydrazine in Drosophila Larvae

Abstract

A pair of pyrene- and anthracene-based turn-on fluorescent probes (1 and 2, respectively) reported here can be easily synthesized in a single-step process and also exhibit outstanding sensing behavior toward hydrazine over various competing nucleophilic species and environmentally relevant ions. The probes display dramatic enhancements in the emission intensity with as high as 83- and 173-fold increases in the presence of hydrazine. Nitrogenous bases, thiols, and lanthanides do not interfere in the fluorometric detection. These probes enable the detection of hydrazine with the naked eye well below sub-ppm concentrations (ca. 30 ppb) with analytical detection limits of 5.4 ppb for 1 and 7.7 ppb for 2, which are far exceeded by the accepted lower limit for hydrazine (10 ppb) set by the US EPA. Simple paper strips based on these probes could be used for the detection of hydrazine even in the gas phase. Both of the probes could selectively detect hydrazine even in pond water samples efficiently. The probes were successfully applied to visualize, for the first time, accumulation of hydrazine in live fruit-fly larvae using epifluorescence microscopy. The novel and interesting detection mechanism, proposed on the basis of spectroscopic evidence and single crystal XRD results, indicates that the detection pathway proceeds via the initial step of a five-membered ring formation upon attack of the hydrazine, followed by a dehydration step for gaining aromaticity.

Recent Developments in Fluorometric and Colorimetric Chemodosimeters Targeted towards Hydrazine Sensing: Present Success and Future Possibilities

“…Bandyopadhyay and co‐workers designed two “turn‐on” fluorescent chemodosimeter 63 containing phenanthrene group and 64 containing anthracene group for the intracellular detection of hydrazine (Figure ). Probe 63 exhibits 83‐fold and probe 64 displays 173‐fold emission enhancement in response to hydrazine in H 2 O/MeOH (4:1, v/v) solution.…”

Recent progress in the development of fluorescent probes for hydrazine

“…Recently, Bandyopadhyay and co‐workers developed a pair of pyrene‐ and anthracene‐based turn‐on fluorescent probes ( 63 and 64 ) for hydrazine (Figure ) . These two probes can be easily obtained in a single‐step process by condensing acetylacetone with 1‐pyrenecarboxaldehyde and 9‐anthraldehyde, respectively.…”

“…[92] The fluorescence of the probe was quenched due to Figure 34). [93] These two probes can be easily…”

Nanoporous Silica-Dye Microspheres for Enhanced Colorimetric Detection of Cyclohexanone

“…The designed sensing mechanism was based on nucleophilic addition by the three equivalent amino groups of the dye to the carbonyl moiety of cyclohexanone in the formation of an imine species [46][47][48][49], leading to changes in the UV-vis absorption band that allows for the direct identification of low or high concentration by the naked eye (Figure 3).…”