Ultrahigh Supramolecular Cascaded Room-Temperature Phosphorescence Capturing System.

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Photochemistry

Background:

• Supramolecular chemistry enables the design of complex molecular architectures.
• Phosphorescence-based materials offer unique optical properties for sensing and imaging.
• Host-guest complexation and self-assembly are key strategies for creating functional nanomaterials.

Purpose of the Study:

• To construct an ultrahigh supramolecular cascaded phosphorescence-capturing aggregate.
• To investigate the phosphorescence enhancement and energy transfer properties of the aggregate.
• To explore the application of the aggregate as an imaging agent for multicolour cell labeling.

Main Methods:

• Multivalent co-assembly of cucurbit[7]uril (CB[7]) and amphipathic sulfonatocalix[4]arene (SC4AD).
• Host-guest interaction between a dibromophthalimide derivative (G) and CB[7] to initiate phosphorescence.
• Formation of spherical nanoparticles (G⊂CB[7]@SC4AD) with enhanced phosphorescence lifetime and intensity.
• Investigation of phosphorescence energy transfer (PET) to various acceptors (RhB, DBT, Cy5, NiB).

Main Results:

• A 40-fold enhancement in phosphorescence intensity and a lifetime of 1.13 ms were achieved.
• High phosphorescence energy transfer efficiency (up to 84.4%) and antenna effect (up to 289.4) were observed.
• Cascaded energy transfer was demonstrated from 425 nm to 800 nm.
• The aggregate successfully functioned as an imaging agent for multicolour cell labeling.

Conclusions:

• The constructed supramolecular aggregate exhibits significantly enhanced phosphorescence properties.
• Efficient cascaded phosphorescence energy transfer was achieved through a multi-component system.
• The developed material holds promise for advanced multicolour cell imaging applications.