快速合成的自组装银纳米花对 pH 值响应性研究

由于自组装过程对周围环境的敏感性,使得快速合成稳定组装体仍然是一个巨大的挑战。文章以4,6-二氨基-2-巯基嘧啶(DAMP)为配体,在室温条件下通过简单的搅拌,在5 min之内成功合成了一种发射在波长为570 nm的新型银纳米团簇(Ag-DAMP),并自组装成具有磷光和稳定光学活性的有序微结构纳米花;纳米花的荧光寿命延长至5.83 $ \mu $s,光致发光(PL)信号表现出循环的pH值响应性。研究发现,纳米花悬浮液加入HCl后图案迅速消失,经NaOH处理后该图案又重新出现,因此可用于荧光防伪。研究结果表明,该荧光材料对金属纳米团簇自组装成超分子聚集体的防伪材料开发应用具有重要意义。

Rapid synthesis of stable assemblies is still a great challenge due to the sensitivity of the self-assembly process to the surrounding environment. Employing 4,6-diamino-2-mercaptopyrimidine(DAMP) as the ligand, novel silver nanoclusters(Ag-DAMP) emitting at 570 nm were successfully synthesized within 5 minutes at room temperature by simple stirring, which further self-assembled into ordered microstructured nanoflowers with phosphorescence and stable optical activity. The fluorescence lifetime of the nanoflowers was extended to 5.83 $ \mu $s, and the photoluminescence(PL) signal showed cyclic pH responsiveness. The results show that the pattern of nanoflower suspension disappears quickly after adding HCl, and reappears after NaOH treatment, which can be used for fluorescence anti-counterfeiting. The results indicate that this fluorescent material is of great significance for the development and application of anti-counterfeiting materials in which metal nanoclusters self-assemble into supramolecular aggregates.