Clusteroluminescence from Random Aggregation of Micrometers to Ordered Assembly of Sub-10 Nanometers by Space-Confined Template Synthesis

Clusteroluminescence (CL) clusters in the absence of aromatic or π-conjugated structures have emerged as a new family of luminescent materials due to their abundant sources and inherent biocompatibility. However, there is an inborn challenge in controlling the size of CL clusters from random aggregation of micrometers to ordered assembly of sub-10 nanometers. Such an inherent drawback significantly restricts their progress from theoretical research to practical applications. To address this obstacle, a novel approach using space-confined templates is proposed to synthesize CL clusters with tunable sizes. Space-confined templates with sizes of ≈2–6 nm are constructed to effectively confine non-aromatic molecules, yielding size-controllable and luminescence-tunable CL clusters. The versatility of this synthetic strategy is further proved by using non-conjugated molecules, such as L-valine and L-isoleucine. Finally, the potential applications of the synthesized CL clusters have been implemented in cell nucleus imaging owing to their sub-10 nm size and efficient luminescence. The success of this work not only offers a versatile space-confined approach to synthesize size-tunable CL clusters within sub-10 nm, but also opens new avenues for the deployment of CL clusters in advanced applications.