Capture and Release of Molecules with Liquid Metals

Area of Science:

• Materials Science
• Surface Chemistry
• Microfluidics

Background:

• Liquid metals (LM) offer unique properties for advanced applications.
• Functionalizing LM surfaces is key to controlling molecular interactions.
• Existing capture and release methods face limitations in microfluidic environments.

Purpose of the Study:

• To develop a novel method for capturing and releasing target molecules using gallium-based liquid metal.
• To functionalize the liquid metal oxide surface for enhanced molecular binding.
• To demonstrate the reusability and microfluidic compatibility of the capture and release system.

Main Methods:

• Functionalizing the native oxide of gallium-based liquid metal with (3-aminopropyl)triethoxysilane (APTES).
• Utilizing the amine-terminated surface for capturing fluorescein isothiocyanate (a model analyte).
• Employing electrochemical reduction to release captured molecules and spontaneous oxide reformation for reusability.

Main Results:

• Achieved ≈81% capture efficiency of the model dye from solution.
• Demonstrated ≈92% release efficiency of captured molecules.
• Showcased superior stability compared to electrostatic methods in microfluidic shear forces.
• Observed multilayer capture, increasing binding capacity per surface area.

Conclusions:

• The oxide-mediated capture and release strategy using functionalized liquid metal is a versatile proof-of-concept.
• The system demonstrates high efficiency, reusability, and microfluidic compatibility.
• This methodology holds potential for integration into lab-on-a-chip devices for drug delivery, bioseparation, and sensing.