Atomically precise ligand engineering of gold nanoparticles via interphase mass transfer

Area of Science:

• Nanotechnology
• Materials Science
• Biomedical Engineering

Background:

• Precise surface engineering of gold nanoclusters (Au NCs) is essential for advanced bioimaging applications.
• Conventional ligand exchange methods often lead to structural damage and uncontrolled ligand distribution on Au NCs.

Purpose of the Study:

• To develop a novel method for structure-preserving, high-yield surface modification of Au NCs.
• To investigate the impact of ligand density on the biodistribution of Au NCs for targeted organ delivery.

Main Methods:

• An interphase-assisted ligand exchange method was developed, utilizing mass transfer resistance between immiscible phases.
• Controlled mass transfer of ligands was achieved, suppressing etching side reactions while maintaining exchange kinetics.
• Systematic introduction of p-aminothiophenol (p-ATP) ligands onto Au25 NCs was performed.

Main Results:

• The interphase-assisted method enabled high-yield substitution of diverse thiol ligands without compromising Au NC structure.
• Increasing p-ATP ligand density on Au25 NCs successfully shifted their biodistribution from liver and spleen to kidneys in mice.
• The study demonstrated precise control over Au NC surface modification at a molecular level.

Conclusions:

• The developed interphase-assisted method offers a robust platform for precise surface engineering of metal nanomaterials.
• Ligand engineering on Au NCs provides a tunable approach for controlling biodistribution and achieving targeted organ delivery.
• This methodology advances the understanding of ligand-nanomaterial interactions for bioimaging and therapeutic applications.