Rapid Deposition and Controlled Clustering of Gold Nanoparticles on Surfaces and Micro-Patterned Substrates

Area of Science:

• Materials Science
• Nanotechnology
• Surface Chemistry

Background:

• Gold nanoparticles (AuNPs) are crucial for applications in sensing and surface-enhanced Raman spectroscopy (SERS).
• Uniform and scalable deposition of AuNPs onto substrates remains a significant challenge.
• Controlling nanoparticle aggregation and surface distribution is key for optimizing performance.

Purpose of the Study:

• To develop a rapid, scalable, and uniform method for depositing gold nanoparticles (AuNPs) onto centimeter-scale substrates.
• To control the morphology and optical response of deposited AuNPs by tuning aggregation.
• To demonstrate selective deposition of AuNPs into patterned nanostructures.

Main Methods:

• Dispersing poly(ethylene glycol) (PEG)-functionalized AuNPs in dichloromethane (DCM) with cetyltrimethylammonium chloride (CTAC).
• Utilizing centrifugal force for uniform deposition onto hydroxyl-terminated surfaces.
• Controlling AuNP clustering by adjusting CTAC concentration.
• Selective removal of AuNPs from surfaces using wiping after deposition into nanowells.

Main Results:

• Achieved rapid and uniform deposition of AuNPs as nonagglomerated submonolayers or tunable clusters.
• Demonstrated control over AuNP morphology and optical properties through CTAC concentration.
• Successfully deposited AuNPs into nanowells of patterned substrates with high uniformity.
• Showcased selective deposition capabilities for patterned surfaces.

Conclusions:

• The centrifugal deposition method offers a scalable and efficient approach for AuNP assembly.
• Tunable control over AuNP aggregation enables tailored optical properties for specific applications.
• The technique is suitable for large-scale selective deposition of AuNPs onto patterned surfaces for SERS and sensor development.