Effect of Au Nanoparticle Agglomeration on SERS Signal Amplification

Area of Science:

• Nanotechnology
• Spectroscopy
• Materials Science

Background:

• Surface-enhanced Raman spectroscopy (SERS) performance is critically dependent on nanoparticle (NP) morphology.
• Controlling NP size and agglomeration is key to enhancing SERS signal intensity and detection sensitivity.
• Aerosol dry printing (ADP) offers a method for fabricating SERS-enhancing structures with tunable NP characteristics.

Purpose of the Study:

• To investigate the impact of nanoparticle agglomeration on SERS signal enhancement.
• To evaluate different NP modification techniques for optimizing SERS substrate performance.
• To demonstrate the potential of ADP for creating cost-effective and highly efficient SERS substrates.

Main Methods:

• Fabrication of SERS-enhancing structures using aerosol dry printing (ADP).
• Modification of aerosol NPs using pulsed laser radiation and thermal treatment.
• Analysis of SERS signal enhancement using methylene blue as a model analyte.
• Correlation of NP agglomeration degree with SERS signal amplification.

Main Results:

• SERS signal enhancement is strongly influenced by the ratio of individual NPs to agglomerates in the printed structure.
• Structures composed primarily of non-agglomerated NPs exhibit superior SERS signal amplification.
• Laser-modified NPs resulted in better SERS enhancement compared to thermally modified NPs due to reduced secondary agglomeration.
• Increased gas flow during ADP processing minimized secondary agglomeration, improving NP distribution.

Conclusions:

• The agglomeration state of NPs is a critical factor in SERS substrate efficiency.
• Aerosol dry printing, particularly with laser-modified NPs, enables the production of high-performance SERS substrates.
• Optimizing NP agglomeration control through printing conditions and modification techniques is essential for developing advanced SERS applications.