Ultrastable Gold Nanostars via Bottlebrush-like Block Copolymers

Area of Science:

• Nanotechnology
• Materials Science
• Chemistry

Background:

• Gold (Au) nanostars are plasmonic nanostructures with applications in sensing, catalysis, and therapy.
• Traditional synthesis methods yield Au nanostars with limited photo, thermal, and chemical stability.

Purpose of the Study:

• To develop a novel synthesis route for ultrastable colloidal gold nanostars.
• To investigate the stability and properties of polymer-ligated Au nanostars.

Main Methods:

• Synthesis of Au nanostars using bottlebrush-like block copolymers (BBCPs) as cross-linkers for Au3+ ions.
• Characterization of nanostar stability under thermal and laser stress.
• Visualization of plasmonic fields using ultrafast electron microscopy (UEM).

Main Results:

• Ultrastable colloidal Au nanostars were successfully synthesized without the need for Au seeds.
• Polymer-ligated Au nanostars demonstrated significantly enhanced stability compared to CTAB-mediated counterparts.
• High laser stability allowed UEM imaging without morphological degradation, revealing plasmonic fields along star arms.

Conclusions:

• BBCP-mediated synthesis offers a route to highly stable Au nanostars.
• Enhanced stability broadens the potential of Au nanostars in demanding sensing applications.
• Polymer ligation does not impede plasmonic field localization, maintaining sensing capabilities.