Switching Plasmons: Gold Nanorod-Copper Chalcogenide Core-Shell Nanoparticle Clusters with Selectable...

Area of Science:

• Nanotechnology and Materials Science
• Plasmonics
• Optical Engineering

Background:

• Controlling near-infrared (NIR) plasmonic responses of nanomaterials is crucial for novel applications.
• Anisotropic nanoparticle clusters offer unique optical properties due to their structure and composition.

Purpose of the Study:

• To create anisotropic core-shell nanoparticle clusters (NPCs) with tunable NIR plasmonic properties.
• To investigate the interplay between metallic and semiconductor plasmonic responses within a single nanostructure.
• To explore the potential of these NPCs for bioapplications.

Main Methods:

• Fabrication of gold nanorod (AuNR) core-shell nanoparticle clusters using electrostatic self-assembly.
• Modification of the shell via Cd(2+)/Cu(+) cation exchange to form copper selenide (Cu(2-x)Se).
• Characterization of optical properties under varying vacancy doping levels in the Cu(2-x)Se shell.

Main Results:

• The AuNR@Cu(2-x)Se NPCs exhibit tunable NIR plasmonic responses, switching between metallic, semiconductor, and hybrid states.
• Copper selenide shell doping (x > 0) introduces semiconductor plasmonic modes, influencing the overall NIR spectrum.
• Reversible conversion between AuNR@Cu2Se and AuNR@Cu(2-x)Se allows for switching between plasmonic characters.

Conclusions:

• These well-defined colloidal assemblies provide a versatile platform for studying plasmonic metal-semiconductor crosstalk.
• The tunable NIR optical properties across different windows make them promising for bioapplications.
• The ability to achieve all-metallic, metallic/semiconductor, or all-semiconductor plasmonic responses is a key advancement.