A sequential light-harvesting system with thermosensitive colorimetric emission in both aqueous solution and hydrogel

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Photochemistry

Background:

• Natural photosynthesis utilizes sequential energy transfer and temperature sensitivity for efficiency.
• Artificial light-harvesting systems (LHS) aim to mimic these natural processes.
• Developing thermosensitive materials with tunable properties is an active research area.

Purpose of the Study:

• To design and construct an artificial thermosensitive sequential light-harvesting system (LHS).
• To investigate the self-assembly behavior and temperature response of an amphiphilic molecule TPEO.
• To achieve two-step Förster Resonance Energy Transfer (FRET) using specific acceptors within the system.

Main Methods:

• Self-assembly of amphiphilic TPEO molecule into fluorescent nanoparticles in aqueous solution.
• Incorporation of Eosin Yellow (ESY) as the first acceptor and Near-Infrared dye (NiR) as the second acceptor.
• Characterization of nanoparticle properties and investigation of temperature-dependent fluorescence and colorimetric changes.

Main Results:

• TPEO self-assembled into nanoparticles exhibiting tunable Lower Critical Solution Temperature (LCST) behavior.
• A two-step FRET process was successfully established within the nanoparticles using ESY and NiR.
• The system displayed thermosensitive colorimetric fluorescence in both aqueous solutions and hydrogels.

Conclusions:

• An artificial thermosensitive sequential light-harvesting system was successfully constructed.
• The system leverages the combination of LCST behavior and sequential FRET for tunable optical responses.
• This work provides a novel platform for developing smart materials with applications in sensing and imaging.