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A Simple Method for the Size Controlled Synthesis of Stable Oligomeric Clusters of Gold Nanoparticles under Ambient Conditions
Published on: February 5, 2016
Equilibrium gold nanoclusters quenched with biodegradable polymers.
Avinash K Murthy1, Robert J Stover, Ameya U Borwankar
1McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, USA.
ACS Nano
|December 13, 2012
Summary
Researchers developed a novel method to create controlled-size gold nanoclusters using a polymer stabilizer. These nanoclusters can reversibly dissociate, offering potential in biomedical imaging and sensing applications.
Area of Science:
- Materials Science
- Nanotechnology
- Colloid Science
Background:
- Controlling the morphology and chemical properties of sub-100 nm metal nanoclusters is challenging.
- Nanoclusters are of significant interest in biomedical imaging, sensors, and catalysis.
Purpose of the Study:
- To present a new concept for assembling equilibrium gold nanoclusters with controlled sizes.
- To tune nanocluster size by manipulating colloidal interactions with a polymeric stabilizer.
Main Methods:
- Assembly of gold nanoclusters by mixing gold nanospheres with a triblock copolymer solution (PLA-b-PEG-b-PLA).
- Control of nanocluster size (~20-40 nm) by varying gold nanoparticle concentration, polymer/gold ratio, and surface charge.
- Utilizing partial solvent evaporation to induce nanocluster formation.
Main Results:
- Achieved equilibrium gold nanoclusters with tunable sizes from ~20 to ~40 nm.
- Demonstrated reversible dissociation of nanoclusters upon polymer biodegradation.
- Developed a free energy model that semiquantitatively predicts equilibrium cluster size based on particle and polymer concentrations.
Conclusions:
- The developed method allows for controlled assembly and disassembly of gold nanoclusters.
- The tunable size and NIR extinction properties make these nanoclusters promising for biomedical imaging.
- Colloidal interactions, governed by polymer stabilizers, are key to controlling nanocluster formation and properties.
