Preparation of DNA-Templated Silver Nanoclusters Under Macromolecular Crowding Conditions

摘要

DNA-templated silver nanocluster has been used as a novel fluorescent probe for cell imaging and biomolecule detection. The preparation and fluorescence character of silver clusters is largely dependent on DNA templates and solvent environment. Much previous work has been focused mainly on designing optimal DNA templates for the preparation of silver nanoclusters. However, the effects of surrounding solvent, especially intracellular crowded environment on silver clusters are still poorly understood. Here, we examined the effect of dextran induced macromolecular crowding on silver nanoclusters. It was found that the silver nanoclusters prepared in the crowded environment filled with high density of dextrans demonstrated much smaller particle size and much higher fluorescence quantum yield compared with that in water solution. Based on this finding, we further optimize this crowded solvent condition to prepare high-quantum-yield silver nanoclusters.