An efficient fluorescent aggregates for selective recognition of 4-nitrophenol based on 9,10-dihydrobenzo[a]pyrene-7(8 H)-one

[Display omitted] •A novel fluorescent aggregates of 9,10-dihydrobenzo[a]pyrene-7(8H)-one is synthesized.•It produces distinct fluorescent crystalline microstructures from 0-D to 1-D.•The aggregates displayed excellent selectivity toward nitro-explosive 4-NP.•The fluorescent aggregates coated TLC strips detect 4-NP for an instant ‘naked eye’ response.•It is also applied to determine the concentration of 4-NP in real solid samples. A noteworthy fluorescence swelling was realized by designing a fluorescent polyaromatic molecule 9,10-dihydrobenzo[a]pyrene-7(8 H)-one (9,10-DHBaP) through aggregation-induced emission enhancement (AIEE) effect. The nano/microparticles can be engineered through molecular self-aggregation by steadily increasing the water volume percentages in mixed aqueous media. A significant fluorescence enhancement with a red shifted broad band both in absorption and emission spectrum of the aggregates has indicated the formation of J-aggregates. The aggregation characteristics have been investigated by spectroscopic and microscopic techniques. Morphology of the aggregated particles changes from rhombus to hexagonal type. The brilliant cyan emissive fluorescent hydrosol has been utilized as a sensor with superb selectivity and sensitivity toward water soluble nitro-explosive 4-nitro phenol (4-NP) compared to other nitro-aromatics. The limit of detection (LOD) is calculated to be 7.14 nM. The fluorescent paper strips are employed for instant ‘naked eye’ recognition of 4-NP in solid state that expose the technique fast, inexpensive, simple and practical for on-site finding of such pollutant.