Aldehyde-specific Quinazoline Ring-Closure for Highly Sensitive Fluorescent and Redox Formaldehyde Detection
作者:Wei Huang、Fuxing Shen、Dayu Wu
DOI:10.1246/cl.150193
日期:2015.7.5
Structurally tunable small signaling molecules have been specifically designed to probe-free formaldehyde concentrations as low as 0.1 ppm, establishing the utility of probing the exposure limit for safe human consumption according to the guidelines suggested by W.H.O. The substrate, 2-aminobenzoylhydrazide, fluorescent core skeleton was designed for the construction of diverse quinazoline compounds with combinatorial substituent-pending potentials via rapid condensation reactions with aldehyde groups. After identifying the fluorescent species by 1H NMR and X-ray crystallography, we demonstrate that the fluorescent emission is substituent dependent and that, by simple structural variation, the fluorescence can be tunable through controlling internal charge transfer (ICT) within a dye platform. Finally, by introducing more electron-rich ferrocene into the substrate to further undermine the ICT process, we demonstrate highly sensitive formaldehyde sensing through dual signal output, including fluorescence and redox potential.
结构可调的小信号分子经过专门设计,可无探针检测低至 0.1 ppm 的甲醛浓度,从而根据世界卫生组织建议的指南,建立探测人类安全消费暴露限值的效用。底物 2-氨基苯甲酰肼荧光核心骨架被设计用于通过与醛基的快速缩合反应构建具有组合取代基待定电位的多种喹唑啉化合物。通过 1H NMR 和 X 射线晶体学鉴定荧光物质后,我们证明荧光发射取决于取代基,并且通过简单的结构变化,可以通过控制染料平台内的内部电荷转移 (ICT) 来调节荧光。最后,通过在基材中引入更多富电子二茂铁以进一步破坏ICT过程,我们通过双信号输出(包括荧光和氧化还原电位)展示了高灵敏度的甲醛传感。