Self-Assembled Nanohelixes Driven by Host-Guest Interactions and Metal Coordination

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Nanotechnology

Background:

• Self-assembled helical nanostructures are of great interest due to their unique aesthetics and functionalities.
• Achiral aggregation-induced emission (AIE) luminogens offer tunable photophysical properties.

Purpose of the Study:

• To develop a facile method for constructing self-assembled nanohelices (NH) using an achiral AIE luminogen and pillar[5]arene.
• To investigate the role of host-guest interactions and metal coordination in inducing helicity and controlling nanostructure morphology.
• To explore the photophysical properties and potential applications of the resulting nanohelices.

Main Methods:

• Utilized host-guest complexation between an AIE luminogen (G) and pillar[5]arene (H) to induce conformational changes.
• Employed Ag(I) coordination to drive the formation of 1D assemblies and hexagonal packing into nano-sized fibers.
• Investigated synthesis in both homogeneous and heterogeneous conditions.
• Evaluated luminescence, reactive oxygen species (ROS) production, bacteria imaging, and photodynamic antibacterial activity.

Main Results:

• Successfully constructed self-assembled nanohelices (NH) via supramolecular assembly.
• Achieved boosted luminescence and enhanced reactive oxygen species (ROS) productivity due to restricted molecular motion within the NH.
• Demonstrated the feasibility of the strategy in both homogeneous and heterogeneous synthesis.
• Confirmed the capacity of NH for bacteria imaging and photodynamic antibacterial activity against Staphylococcus aureus and Escherichia coli.

Conclusions:

• Developed a versatile strategy for fabricating helical nanostructures with tunable photophysical properties.
• The supramolecular assembly approach concurrently regulates NH morphology and luminescence.
• The synthesized nanohelices show promise for applications in bacteria imaging and photodynamic therapy.