Morphology-Invariant Metallic Nanoparticles with Tunable Plasmonic Properties.

Area of Science:

• Nanotechnology
• Materials Science
• Plasmonics

Background:

• Traditional tuning of metallic nanoparticle plasmonic properties relies on altering size and shape.
• Morphological variations in plasmonic nanoparticles can negatively impact their performance in applications.
• A need exists for morphology-invariant plasmonic nanoparticles with tunable properties.

Purpose of the Study:

• To develop a novel method for engineering morphology-invariant plasmonic nanoparticles.
• To demonstrate tunable plasmonic properties by controlling the internal structure of nanoparticles.
• To showcase the application of these nanoparticles in sensitive colorimetric sensing.

Main Methods:

• Synthesized Ag@(Ag-Au) shell@shell nanocages via selective silver growth on preformed Ag-Au alloyed nanocage seeds.
• Controlled plasmonic properties by varying the amount of silver deposited on inner surfaces.
• Maintained consistent overall nanocage morphology throughout the tuning process.

Main Results:

• Achieved tunable plasmonic properties in Ag@(Ag-Au) nanocages by controlling internal silver deposition.
• Demonstrated morphology invariance, as the overall nanocage structure remained unchanged.
• Successfully applied the engineered nanocages for sensitive colorimetric detection of human carcinoembryonic antigen (CEA).

Conclusions:

• A novel strategy using internal structure control enables the creation of morphology-invariant plasmonic nanoparticles.
• This approach offers convenient and effective tuning of plasmonic properties.
• The developed Ag@(Ag-Au) nanocages show significant potential for ultrasensitive biosensing applications.