Fabrication of Flexible Pyramid Array as SERS Substrate for Direct Sampling and Reproducible Detection

Area of Science:

• Materials Science
• Analytical Chemistry
• Nanotechnology

Background:

• On-site analysis demands rapid extraction and detection of molecules from diverse surfaces.
• Existing methods often lack efficiency and sensitivity for irregular sample matrices.

Purpose of the Study:

• To develop a flexible and reusable platform for surface-enhanced Raman scattering (SERS) analysis.
• To create a substrate capable of rapid molecule extraction and sensitive detection.

Main Methods:

• Fabrication of an ordered polymer pyramid array with half-embedded silver nanoparticles (AgNPs) using a silicon template.
• Development of a 'paste and peel off' method for rapid sample extraction.
• Utilizing the unique nanostructure to enhance SERS 'hot spots' for increased sensitivity.

Main Results:

• The flexible substrate demonstrated efficient rapid extraction of analytes.
• High sensitivity and repeatability were achieved due to uniform pyramid structures and robust 'hot spots'.
• Successful detection of thiram molecules on fruit surfaces with low detection limits (2.4-3 ng/cm²).

Conclusions:

• The developed polymer pyramid SERS substrate is highly effective for in situ analysis.
• The reusable silicon template offers a cost-effective fabrication approach.
• This platform shows significant potential for practical applications in food safety and environmental monitoring.