Progressive aggregation-induced emission strategy for imaging of aluminum ions in cellular microenvironment.

A progressive aggregation-induced emission (AIE) strategy is established based on two diverse stimulus-responsive patterns of copper nanoclusters (CuNCs) for imaging of aluminum ions (Al) in cellular microenvironment. The non-emissive CuNCs were facilely synthesized with l-glutathione (GSH) as both stabilizing agent and reducing agent, and demonstrated the excellent AIE characteristics in the ethanol/water mixture. Moreover, the dispersed CuNCs can be aggregated to give the AIE behavior in aqueous solutions by reducing the pH value, and could be further aggregated with 94-fold reinforce by introducing Al ascribe to the strong coordination ability between Al and the functional groups of GSH, demonstrating the progressive AIE process. Under endocytosis, the progressive AIE strategy can be employed to distinguish the Al in the locations of lysosome against other organelles due to the acidic microenvironment of lysosome. The progressive AIE advantages of CuNCs provide a new concept for signal transduction, and have the promising applications in decoding the functions of intracellular biomolecules.