Study on lawsone derivatives and PVC-modified with lawsone moieties as chemosensors for the detection of nitro-explosives as well as Fe 3+

Lawsone and its derivatives have a variety of applications in the field of pharmaceutical research: as drug candidates, reagents for the chelation and recognition of metal cations (including those for catalytic applications), chemosensors for anions, and materials for energy storage applications. Moreover, there are some reports on the application of lawsone and its derivatives in the forensic science field. One of the most attractive features of lawsones is their bright color and well-pronounced fluorescence, which can be altered due to covalent or non-covalent interactions with various species. In this work, we endeavor to present our recent findings on the fluorescence response of lawsone and its methyl ester to nitro compounds and explosives components, such as 2,4-dinitrotoluene (DNT), 2,4,6-trinitrotoluene (TNT), 2,4,6-trinitrophenole (picric acid, PA), 2-nitromesitylene (2-NM), 4-nitrophenol (NP) as well as Fe3+ (FeCl3). In all the cases a dramatic fluorescence turn-off response was observed with up to 104 M-1 quenching constants. To explore the practical application of lawsone derivatives a mechanochemical modification of polyvinyl chloride (PVC) with lawsone residues was carried out, and thus obtained polymer was found to exhibit a pronounced fluorescence turn-off response to the both nitro-compounds and Fe3+ with as high as 104 M–1 quenching constants.