Plasmon-Free Polymeric Nanowrinkled Substrates for Surface-Enhanced Raman Spectroscopy of Two-Dimensional Materials

Area of Science:

• Materials Science
• Nanotechnology
• Spectroscopy

Background:

• Surface-enhanced Raman spectroscopy (SERS) typically relies on plasmonic nanostructures.
• Developing plasmon-free substrates offers an alternative for SERS applications.

Purpose of the Study:

• To create plasmon-free polymeric nanowrinkled substrates for SERS.
• To investigate the fabrication and properties of these novel substrates.
• To demonstrate their efficacy in enhancing the detection of specific materials.

Main Methods:

• Fabrication of poly(ethylene glycol)diacrylate (PEGDA) substrates with hierarchical wrinkled patterns.
• Utilizing plasma treatment to induce buckling and create nanowrinkles.
• Characterizing wrinkle morphology and its dependence on polymer concentration and molecular weight.
• Testing SERS performance for graphene and hexagonal boron nitride (h-BN) detection.

Main Results:

• A simple, rapid, and cost-effective method for producing plasmon-free wrinkled polymer substrates.
• Hierarchical wrinkled patterns, transitioning from micron to nano-scale, were achieved.
• Reproducible and stable nanowrinkled substrates were obtained.
• Significantly enhanced Raman signal for graphene (8x) and h-BN (50x) compared to SiO2/Si.

Conclusions:

• Plasmon-free polymeric nanowrinkled substrates are viable for SERS.
• The fabrication method offers a cost-effective and scalable approach.
• These substrates demonstrate superior enhancement for detecting 2D materials like graphene and h-BN.