Goswami Nidhi, Naithani Sudhanshu, Goswami Tapas, Kumar Pankaj, Kumar Sushil
Department of Chemistry, Applied Science Cluster, University of Petroleum and Energy Studies (UPES), Dehradun 248007, Uttarakhand, India.
Department of Chemistry, Applied Science Cluster, University of Petroleum and Energy Studies (UPES), Dehradun 248007, Uttarakhand, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2024 Apr 5;310:123971. doi: 10.1016/j.saa.2024.123971. Epub 2024 Jan 28.
A quinoline-derived Schiff base QnSb has been synthesized for fluorescent and colorimetric recognition of Al ions in a semi-aqueous medium. The compound QnSb has been characterized by elemental analysis, FT-IR, H/C NMR, UV-Vis and fluorescence spectral techniques. The crystal structure of the QnSb was confirmed by single crystal X-ray diffraction (SC-XRD) analysis. Notably, almost non-fluorescent QnSb served as a 'turn on' responsive probe for Al by inducing a remarkable fluorescence enhancement at 422 nm when excited at 310 nm. The probe QnSb exhibited high selectivity for Al in CHCN/HO (4:1, v/v) solution over several competing metal ions (e.g., Mg, Pb, Zn, Cd, Co, Cu, Ca, Ni, Fe, Cr, Mn, Sn, and Hg). The limit of detection (LoD) was computed as low as 15.8 nM which is significantly lower than the permissible limit set by WHO for Al ions in drinking water. A 1:1 binding stoichiometry of complex QnSb-Al was established with the help of Job's plot, ESI-MS, NMR and DFT analyses. Based on its remarkable sensing ability, the probe QnSb was utilized to establish molecular logic gates, and the fluorescence detection of Al could clearly be demonstrated on the filter paper test strips.
一种喹啉衍生的席夫碱QnSb已被合成，用于在半水介质中对铝离子进行荧光和比色识别。化合物QnSb已通过元素分析、傅里叶变换红外光谱（FT-IR）、氢/碳核磁共振（H/C NMR）、紫外可见光谱和荧光光谱技术进行了表征。QnSb的晶体结构通过单晶X射线衍射（SC-XRD）分析得到证实。值得注意的是，几乎无荧光的QnSb在310nm激发时，通过在422nm处诱导显著的荧光增强，作为铝的“开启”响应探针。在CHCN/H₂O（4:1，v/v）溶液中，探针QnSb对铝的选择性高于几种竞争性金属离子（如镁、铅、锌、镉、钴、铜、钙、镍、铁、铬、锰、锡和汞）。计算出的检测限（LoD）低至15.8 nM，显著低于世界卫生组织规定的饮用水中铝离子的允许限值。借助Job曲线、电喷雾电离质谱（ESI-MS）、核磁共振和密度泛函理论（DFT）分析，确定了配合物QnSb-Al的1:1结合化学计量比。基于其卓越的传感能力，探针QnSb被用于构建分子逻辑门，并且在滤纸测试条上可以清楚地证明对铝的荧光检测。
