Bhardwaj Kanishk, Anand Thangaraj, Jangir Ritambhra, Sahoo Suban K
Department of Chemistry, Sardar Vallabhbhai National Institute Technology, Surat, Gujarat, 395007, India.
Department of Chemistry, Sathyabama Institute of Science and Technology, Chennai, 600119, India.
J Fluoresc. 2024 Nov;34(6):2917-2926. doi: 10.1007/s10895-023-03503-w. Epub 2023 Nov 14.
Present work introduces an aggregation-induced emission (AIE) active Schiff base 4,4'-((1E,1'E)-([1,1'-biphenyl]-4,4'-diylbis(azaneylylidene))bis(methaneylylidene))bis(5-(hydroxymethyl)-2-methylpyridin-3-ol) (BNPY). Schiff base BNPY was synthesized by reacting benzidine with pyridoxal. The non-fluorescent BNPY in freely soluble DMSO medium showed a significant fluorescence enhancement at 563 nm (λ = 400 nm) upon increasing the water fraction (fw) in DMSO above 60% due to the restriction of intramolecular rotation upon the aggregation of BNPY. The AIE active BNPY was employed for the detection of metal ions in DMSO:HO (fw = 70%). Upon the addition of Fe, the fluorescence emission of BNPY at 563 nm was quenched due to the chelation-enhanced fluorescence quenching (CHEQ). The Job's plot experiment supported the formation of a complex between BNPY and Fe in 1:2 binding ratio. With an estimated detection limit of 5.6 × 10 M, BNPY was employed to detect and quantify Fe ion in real water samples with satisfactory recovery percentages. Moreover, the pH studies of BNPY aggregates revealed three different fluorescence windows: non-fluorescent in acidic pH 2.02 to 3.16, yellow fluorescent between pH 3.60 to 9.33, and green fluorescent in basic pH 9.96 to 12.86.
当前工作介绍了一种聚集诱导发光（AIE）活性席夫碱4,4'-((1E,1'E)-([1,1'-联苯]-4,4'-二基双(氮亚基))双(亚甲基))双(5-(羟甲基)-2-甲基吡啶-3-醇)(BNPY)。席夫碱BNPY通过联苯胺与吡哆醛反应合成。在可自由溶解的二甲基亚砜（DMSO）介质中不发荧光的BNPY，当DMSO中的水含量（fw）增加到60%以上时，由于BNPY聚集时分子内旋转受限，在563nm（λ = 400nm）处荧光显著增强。AIE活性的BNPY用于在DMSO:H₂O（fw = 70%）中检测金属离子。加入Fe后，由于螯合增强荧光猝灭（CHEQ），BNPY在563nm处的荧光发射被猝灭。Job曲线实验支持BNPY与Fe以1:2的结合比形成配合物。BNPY的估计检测限为5.6×10⁻⁶M，用于检测和定量实际水样中的Fe离子，回收率令人满意。此外，BNPY聚集体的pH研究揭示了三个不同的荧光窗口：在酸性pH 2.02至3.16时不发荧光，在pH 3.60至9.33之间呈黄色荧光，在碱性pH 9.96至12.86时呈绿色荧光。
