DFT supported studies of multi-responsive AIE active fluorophores for the sensitive fluorescence recognition of p-nitrophenol and pH: Vapor phase and solution mode sensing

• Published in: Microchemical journal 2024-12, Vol.207, p.112190, Article 112190
• Main Authors: Gul, Kainat, Maria, Assiri, Mohammed A., Majeed, Shumaila, Junaid, Hafiz Muhammad, Shahzad, Sohail Anjum, Farooq, Umar
• Format: Article
• Language: English
• Subjects: DFT studies; J-Aggregates; Multi-responsive sensors; Vapor and liquid phase sensing
• ISSN: 0026-265X
• DOI: 10.1016/j.microc.2024.112190

[Display omitted] •Chromene based multi-responsive sensors showed aggregation-induced emission (AIE) behaviour.•Optical tracing of p-nitrophenol via PET operated fluorescence quenching mechanism.•KG01 and KG02 showed a limit of detection LOD down to 4.7 and 6.6 nM, respectively.•Jobs plot, DLS size distribution, 1H NMR titration and DFT studies endorsed the selective p-nitrophenol sensing.•Sensors KG01 and KG02 were developed for the fluorescence along with visual recognition of TFA and NaOH. Designing of an aggregation-induced emission (AIE) active multi-responsive fluorophores for the sensitive recognition of targeted analytes has been a hot spot in recent time. In pursuit of this endeavor, two chromene core sensors KG01 and KG02, installed with phenyl rotors, were efficiently designed, synthesized, and characterized through NMR spectroscopy. Proposed fluorophores demonstrated striking features of structure–property relationships, including solvatochromism and J-aggregates-based aggregation induced emission (AIE). Subsequently, well-thought-out developed sensors KG01 and KG02 were subjected to photoinduced electron transfer (PET) operated fluorescence quenching driven optical tracing of p-nitrophenol (p-NP) in the co-existence of competing analytes, with LOD down to 4.7 and 6.6 nM, respectively. Further, diversified theoretical calculations were executed to validate J-aggregates, supreme selectivity of sensors towards p-NP and PET as its primary sensing mechanism. Additionally, Jobs plot experiment, dynamic light scattering (DLS) size distribution, and 1H NMR titration assay also endorsed the selective p-NP sensing. Further, reported sensors were exploited for the fluorescence along with visual recognition of trifluoroacetic acid (TFA) and sodium hydroxide (NaOH). Interestingly, devised sensor KG01 disclosed naked-eye detection of TFA vapors. Furthermore, real water sample analysis, engineering of hand-held thin layer chromatography (TLC) plates-based fluorescent kits, and fabrication of logic devices were carried out to signify the convenient point-of-need applications of the proposed sensors. To the best of our knowledge, sensors KG01 and KG02 are first-ever solvatochromic and AIEgen chromenes with good quantum yield (Φ) and absorption coefficient as potential candidates to establish a range of easy-to-apply platforms for the selective and sensitive distinguishing of different aforementioned analytes. Given the role of p-NP as a priority pollutant from