Fabrication of Color-Tunable Gold Nanoclusters and Their Application for Information Encryption

Abstract

The unique luminescence properties of gold nanoclusters (AuNCs) have attracted intense research interest in multiple areas. However, most AuNCs exhibit only a single-color emission. Achieving color-tunable emission through single AuNCs is attractive but still challenging. Herein, a switchable fluorescence strategy was introduced by integrating an aggregation-caused quenching (ACQ)type ligand into an aggregation-induced emission (AIE)-type nanocluster system. In the AIE/ACQ strategy, 4,6-diamino-2-pyrimidinethiol (DPT)-AuNCs with color-tunable emission were developed: in the dimethylformamide (DMF)/water system, the DPT-AuNCs were dissociated and blue fluorescence was obtained, whereas in the MeOH/water system, DPT-AuNCs aggregated and strong orange phosphorescence was obtained. The emission color from orange to blue could also be switched by adjusting the solvent composition. Based on this strategy, the color-tunable AuNCs system was further employed for dynamic information encryption.