The synthesis of fluorescent nanoclusters based on the etching reaction

Thiolate-protected atomically precise nanoclusters (NCs) demonstrate a series of unique luminescent characteristics attributed to their various peculiar electronic structures. Therefore, fluorescent NCs present extraordinary practical values in biosensing and bioimaging research fields. Nevertheless, restricted by the types of fluorescent NCs, there are great difficulties in promoting the development of NCs in fluorescent research areas. As a result, it is of significant necessity for researchers to develop new synthetic pathways to produce high-quality fluorescent NCs. According to the analysis about the structural characteristics of fluorescent NCs, some general features like longer motif and higher ligand-to-metal ratio can be found, consistent to some presented regularities in etching reaction. Consequently, in this work, we used Au₂₅(MHA)₁₈ (MHA = 6-mercaptohexanoic acid) as a model nanocluster and utilized the etching reaction to systematically explore etching products and their corresponding luminescent properties. Moreover, we also identified three main reaction processes in the entire etching reaction process, which can generate new metal nanocluster species with various fluorescent properties. Hence, the etching reaction will provide a good platform to produce new luminescent metal NC species.