Ghosh Suprava, Malakar Chandi C, Pahari Pallab, Kumar Atta Ananta
Department of Basic & Applied Science, National Institute of Technology, Arunachal Pradesh, Jote 791113, India.
Department of Chemistry, National Institute of Technology Manipur, Manipur 795004, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2025 Jan 15;325:125134. doi: 10.1016/j.saa.2024.125134. Epub 2024 Sep 18.
Herein, we report pyrene-tagged amide and urea-based sugar derivatives 1 and 2 in a simple synthetic pathway to recognize I and Hg ions. Both molecules showed absorbance and fluorescence selectivity towards iodide ions in THF/HO (7/3, v/v) medium. The selectivity and sensitivity of 2 for iodide ions are superior to 1 due to more H-bond donors in 2. Interestingly, fluorometric receptor 2 exhibited aggregation-induced emission (AIE) at higher pH with a remarkable fluorometric color change. The AIE phenomenon might be explained by the self-association of 2 after forming imine functionality in the alkali medium. The Stern-Volmer plot showed the fluorescence quenching constant of each receptor with an iodide ion and indicated the quenching pathway. The LODs of 1 and 2 for iodide ions were evaluated as 0.84 and 0.17 µM, respectively. The 1:1 binding stoichiometry of 1 or 2 with iodide was found from the Job plot and verified by measuring the complex mass. Further, the complexes of each receptor with I ions can detect Hg ions selectively by fluorescence turn-on method with low sensitivities (LODs: 0.008 µM for 1 and 0.01 µM for 2). DFT results were used to understand the binding mode of receptors 1 and 2 with iodide ions and the quenching process in the aqueous THF medium. The real application of the receptors was established for the recovery of iodide and Hg ions from natural water samples.
在此，我们报道了通过简单合成途径制备的芘标记的酰胺和脲基糖衍生物1和2，用于识别碘离子和汞离子。在四氢呋喃/水（7/3，v/v）介质中，这两种分子对碘离子均表现出吸光度和荧光选择性。由于2中存在更多的氢键供体，其对碘离子的选择性和灵敏度优于1。有趣的是，荧光受体2在较高pH值下表现出聚集诱导发光（AIE），且有明显的荧光颜色变化。AIE现象可能是由于2在碱性介质中形成亚胺官能团后发生自缔合所致。Stern-Volmer图显示了每个受体与碘离子的荧光猝灭常数，并表明了猝灭途径。1和2对碘离子的检测限分别为0.84和0.17µM。通过Job图确定了1或2与碘离子的1:1结合化学计量比，并通过测量配合物质量进行了验证。此外，每个受体与碘离子的配合物可以通过荧光开启法选择性地检测汞离子，但灵敏度较低（检测限：1为0.008µM，2为0.01µM）。使用密度泛函理论（DFT）结果来理解受体1和2与碘离子的结合模式以及在水相四氢呋喃介质中的猝灭过程。建立了受体在从天然水样中回收碘离子和汞离子方面的实际应用。
