Key Laboratory of Nanobiosensing and Nanobioanalysis at Universities of Jilin Province, Faculty of Chemistry, Northeast Normal University, Changchun 130024, PR China.
Key Laboratory of Nanobiosensing and Nanobioanalysis at Universities of Jilin Province, Faculty of Chemistry, Northeast Normal University, Changchun 130024, PR China.
Int J Biol Macromol. 2024 Mar;262(Pt 2):130195. doi: 10.1016/j.ijbiomac.2024.130195. Epub 2024 Feb 13.
Covalent organic Framework (COFs) has become a new platform for functional research and material design. A novel covalent organic framework (CN-COF) was first synthesized with p-xylylene dicyanide and 2-hydroxy-1,3,5-benzenetrialdehyde through the Knoevenagel condensation reaction. CN-COF is a porous crystal material with strong thermal and chemical stability. CN-COF exhibits a selective "turn-on" fluorescence response to Al in ethanol with blue-shifted emission spectra over the other tested metal ions. The color changes from pink to earth yellow, and the fluorescence effect is clearly visible. The fluorescence intensity of CN-COF was linearly related to the concentration of Al, and the detection limit was 1.815 μM. Importantly, CN-COF exhibits a satisfactory recovery for detecting Al in drinking water and fish samples. CN-COF also showed the intuitive semi-quantitative detection ability for Al via the color change with the naked eyes. The special pore structure is conducive to allow Al enter to coordinate with O and N atoms on the wall of CN-COF scaffold. The revisable fluorescence change upon the selective addition of Al and XRD, EDTA, XPS and DFT results demonstrated the complex process. The inhibition of the photoinduced electron transition from O atoms to Al induced the fluorescence enhancement. This study not only presents a synthesis idea for a new structural organic framework, but also offers a highly selective and sensitive fluorescence chemical sensor for the identification and detection of Al.
共价有机骨架（COFs）已成为功能研究和材料设计的新平台。通过 Knoevenagel 缩合反应，首次用对二甲苯二氰和 2-羟基-1,3,5-苯三甲醛合成了一种新型共价有机骨架（CN-COF）。CN-COF 是一种多孔晶体材料，具有很强的热稳定性和化学稳定性。CN-COF 对乙醇中的 Al 表现出选择性“开启”荧光响应，发射光谱蓝移，对其他测试金属离子没有响应。颜色从粉红色变为土黄色，荧光效果清晰可见。CN-COF 的荧光强度与 Al 的浓度呈线性关系，检测限为 1.815 μM。重要的是，CN-COF 对饮用水和鱼样中的 Al 检测表现出令人满意的回收率。CN-COF 还通过肉眼观察颜色变化表现出直观的半定量检测 Al 的能力。特殊的孔结构有利于 Al 进入并与 CN-COF 支架壁上的 O 和 N 原子配位。选择性加入 Al 后荧光变化的可恢复性以及 XRD、EDTA、XPS 和 DFT 结果表明了这一复杂过程。O 原子向 Al 诱导的光致电子转移的抑制导致荧光增强。本研究不仅提出了一种新结构有机骨架的合成思路，还为 Al 的识别和检测提供了一种高选择性和高灵敏度的荧光化学传感器。
