Sub-1.5 nm-gapped heterodimeric plasmonic nanomolecules

Area of Science:

• Nanotechnology
• Materials Science
• Physical Chemistry

Background:

• Plasmonic molecules, assemblies of nanomaterials with electromagnetic coupling, are crucial but difficult to synthesize due to limited control over structure, composition, and inter-unit coupling.
• Existing methods using DNA nanotechnology face challenges like weak coupling and restricted material choices.

Purpose of the Study:

• To overcome limitations in synthesizing plasmonic molecules and enable precise control over their assembly.
• To develop a general and reliable method for creating homo/heterodimeric plasmonic nanomolecules with diverse metal compositions.

Main Methods:

• Utilized DNA-guided, solvo-driven silver (Ag) ion soldering to construct plasmonic nanomolecules.
• Achieved strong in-solution electric-dipole coupling with sub-1.5 nm interparticle dielectric gaps.
• Synthesized a comprehensive set of 10 combinations of homo/heterodimeric plasmonic nanomolecules using four different metals (Au, Ag, Pt, Pd).

Main Results:

• Successfully fabricated a diverse library of plasmonic nanomolecules with controlled compositions and strong coupling.
• Demonstrated strong electric-dipole coupling in solution for both strongly (Au, Ag) and damped (Pt, Pd) plasmonic materials.
• Achieved sub-1.5 nm interparticle dielectric gaps, crucial for electromagnetic hybridization.

Conclusions:

• The developed method provides a general and reliable route to synthesize plasmonic molecules with tailored properties.
• The inclusion of Pt/Pd opens avenues for plasmon-mediated catalysis.
• Broken dimeric symmetry is beneficial for Fano-like resonance, photonic nanodiodes, and enhancing plasmon dark states.