Chalcone–DPBF aggregation-induced emitters as fluorescent probes for nitroaromatics detection in solution and on paper strips

Three diphenylbenzofulvene (DPBF)–chalcone derivatives were synthesized via a mechanochemical approach and evaluated as luminescent probes –as AIEgens, Aggregation-Induced Emission luminogens– for nitroaromatic compounds. All compounds are weakly emissive in acetonitrile but display strong turn-on emission in ACN/H 2 O mixtures, with λ em ≈ 565–566 nm at water fraction, f w = 95%. Among them, the pyrrole derivative (DPBF_chal_py) shows the largest emission enhancement (due to the AIE effect) and was selected for nitroaromatic sensing (DNB, DNT, 3-NP, PA) in aqueous media. Stern–Volmer (SV) plots revealed the selectivity order PA ≫ 3-NP > DNT > DNB, with Limit of Detection (LOD) of ~3.1, ~1.3, ~0.5 and ~ 0.05 μM, respectively. Spectral-overlap and SV plots based on fluorescence lifetime values indicate the presence of static quenching for DNB/DNT and a dominant primary inner-filter effect (pIFE) for PA and 3-NP, with IFE-corrected plots corroborating this interpretation. Paper strips coated with the probes allow naked-eye detection in solution and vapor phases. These results establish DPBF_chal_py as a robust AIE structure for selective nitroaromatic sensing in water-rich environments and as promising candidate for portable paper-based formats. • Three diphenylbenzofulvene (DPBF)–chalcone derivatives were synthesized using a mechanochemical approach. • While all compounds exhibit weak emission in acetonitrile, they display strong turn-on emission in ACN/H 2 O mixtures, with emission enhancement due to the AIE effect. • DPBF–chalcone derivatives are a robust AIE structure for the sensing of nitroaromatic in water-rich environments. • The three DPBF–chalcone derivatives are promising candidates for use in portable paper-based formats.