银纳米团簇与吡啶羧酸自组装构筑的聚集诱导发光水凝胶

Aggregation-Induced Emission-Active Hydrogels Self-assemblied by Silver Nanoclusters and Pyridine Carboxylic Acids

金属纳米团簇由几个至几百个金属原子组成,通常尺寸在1~10 nm。其中,银纳米簇(Silver Nanoclusters,Ag NCs)具有合成方法简单、荧光发射波长可调等优点,已成为纳米簇领域里发展前景最好的材料之一。Ag NCs的聚集诱导发光(AIE)现象可以通过超分子策略将Ag NCs与不同类型的小分子材料相结合来实现。通过吡啶二羧酸(2,6-DPA)诱导原子精确的银(9)纳米团簇(Ag 9-NCs)自组装,在多重非共价键作用下,构筑了具有AIE特性的水凝胶,其荧光寿命提高了~574倍,荧光寿命达到1.88μs。透射电子显微镜(TEM)和扫描电子显微镜(SEM)的表征结果证明水凝胶由形状特殊的棱形纳米棒组成。红外光谱(FT-IR)和X射线衍射(XRD)的结果证明水凝胶形成的主要驱动力是氢键和π-π堆积作用。这项工作的开展扩展了原子精确纳米团簇自组装行为的研究,为新型纳米团簇AIE凝胶体系的构筑提供了新的研究思路。

Metal nanoclusters consist of a few to several hundred metal atoms,usually with a size of 1 to 10 nm.Because of the advantages of simple synthesis method and tunable fluorescence emission wavelength,silver nanoclusters have become one of the most promising materials in the field of nanoclusters.The aggregation-induced luminescence(AIE)phenomenon of Ag NCs can be achieved by combining Ag NCs with different types of small molecule materials through supramolecular strategies.In this paper,hydrogels with AIE properties were constructed by self-assembly of atomically precise silver nanoclusters(Ag9-NCs)induced by pyridine dicarboxylic acid(2,6-DPA)under multiple non-covalent bonding,whose fluorescence intensity was increased by ~574 times and the fluorescence lifetime reached 1.88 μs.The TEM and SEM demonstrate that the hydrogel consists of prismatic nanorods with special shapes.FTIR and XRD demonstrate that the main driving forces for hydrogel formation are hydrogen bonding and π-π stacking interactions.This work extends the self-assembly behavior of atomically precise nanoclusters and provides a new research idea for the construction of novel nanocluster AIE gel systems.