A Versatile Strategy for Light-Driven Active Transport of Ions

Area of Science:

• Synthetic chemistry
• Supramolecular chemistry
• Membrane transport

Background:

• Biological transport systems are crucial for life processes.
• Synthetic chemists have focused on passive transport, but active transport remains challenging.
• Light offers precise control for driving active transport without waste.

Purpose of the Study:

• To develop a general and robust strategy for light-driven active transport of charged cargos.
• To overcome limitations of existing light-driven transport systems that rely on specific host-guest interactions.

Main Methods:

• Utilized light-controlled membrane permeability and charge complementarity.
• Employed positively charged azobenzene derivatives as light-responsive carriers.
• Coupled photoisomerization to transport across a liquid membrane via a molecular ratchet mechanism.

Main Results:

• Demonstrated light-driven active transport of negatively charged cargos by forming ion pairs.
• Showcased the system's ability to transport various anions simply added as salt.
• Confirmed functionality in buffered solutions.

Conclusions:

• Presented a general strategy for light-driven active transport of charged species.
• The approach leverages charge complementarity and light-controlled membrane permeability.
• This method shows potential for biomedical applications and smart materials.