Solution phase interactions controlled ordered arrangement of gold nanoparticles in dried state

Area of Science:

• Nanotechnology
• Biomaterials Science
• Materials Chemistry

Background:

• Gold nanoparticles (Au NPs) are crucial in various applications.
• Controlling nanoparticle synthesis and assembly is key for advanced materials.
• Biomolecule interactions can influence nanomaterial properties.

Purpose of the Study:

• To synthesize Au NPs using water-soluble biomolecules.
• To investigate the effect of different biomolecules on Au NP morphology and arrangement.
• To understand the interactions between Au NPs and biomolecules.

Main Methods:

• Seed-mediated synthesis of Au NPs at room temperature.
• Characterization using UV-visible spectroscopy, Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD), and X-ray Photoelectron Spectroscopy (XPS).
• Fluorescence spectroscopy to study biomolecule-Au NP interactions.

Main Results:

• Spherical Au NPs with sizes <= 20 nm were synthesized.
• Biomolecules like DNA, chitosan, and phospholipids induced a pearl-necklace arrangement in dried Au NPs.
• Bovine serum albumin (BSA) did not result in the typical pearl-necklace arrangement.
• Favorable interactions between Au NPs and biomolecules were confirmed.

Conclusions:

• Biomolecule-templated synthesis offers control over Au NP size and shape.
• The specific interactions between Au NPs and biomolecules dictate their assembly.
• Dried-state pearl-necklace arrangements are driven by aqueous-phase interactions.