A new fluorescent triazole trindane-coumarin based chemosensor (L1) was designed, synthesized by click chemistry and applied for the detection of various nitroaromatic compounds, such as 1-chloro-4-nitrobenzene, 4-nitrotoluene, 3-nitrotoluene, m-dinitrobenzene, nitrobenzene, 2-nitrotoluene and 1-chloro-2-nitrobenzene, picric acid and p-nitrophenol. Among the tested nitroaromatics, L1 shows selective turn-off fluorescence in the presence of picric acid and p-nitrophenol due to the energy transfer mechanism in aqueous DMSO medium. Without any noticeable interference from the other tested nitroaromatics, sensor L1 can be applied to detect picric acid and p-nitrophenol down to micromolar range. Further, the practical utility of L1 was validated by monitoring the concentrations of picric acid and p-nitrophenol in the real environmental water samples.