Self-assembly and characterization of 2D plasmene nanosheets

Area of Science:

• Materials Science
• Nanotechnology
• Nanophotonics

Background:

• Freestanding plasmonic nanoparticle (NP) superlattice sheets are emerging 2D nanomaterials.
• These materials exhibit tunable properties for applications in sensing, anticounterfeiting, ionic gating, nanophotonics, and flat lenses.
• Existing methods for producing these sheets often involve significant solid support.

Purpose of the Study:

• To present a robust and general two-step drying-mediated approach for fabricating freestanding monolayer plasmonic NP superlattice sheets.
• To detail the fabrication protocol, characterization methods, and key experimental parameters for producing these novel nanomaterials, termed 'plasmene nanosheets'.

Main Methods:

• Developed a two-step drying-mediated approach for NP superlattice sheet fabrication.
• Utilized NP surface functionalization with thiolated polystyrene.
• Employed self-assembly of NPs at the air-water interface.
• Characterized the plasmene nanosheets using optical microscopy, spectrophotometry, TEM/SEM, and AFM.

Main Results:

• Successfully produced freestanding monolayer plasmonic NP superlattice sheets (plasmene nanosheets) with minimal solid support.
• Demonstrated strong plasmonic coupling interactions between closely packed NP building blocks.
• Provided a comprehensive protocol including NP synthesis, surface functionalization, self-assembly, and characterization.

Conclusions:

• The described protocol enables the fabrication of tailored plasmene nanosheets from various NP building blocks.
• Key experimental parameters influencing fabrication are summarized to guide researchers.
• The overall process, from NP synthesis to characterization, is completed in approximately 33.5 hours.