A simple low-cost flexible plasmonic patch based on spiky gold nanostars for ultra-sensitive SERS sensing

Area of Science:

• Nanotechnology
• Analytical Chemistry
• Materials Science

Background:

• Transparent and flexible surface-enhanced Raman scattering (SERS) substrates are crucial for point-of-care detection on irregular surfaces.
• Developing cost-effective and highly sensitive SERS platforms remains a significant challenge.

Purpose of the Study:

• To create a simple, cost-effective, flexible SERS patch for ultra-high sensitivity detection.
• To investigate the SERS performance of gold nanostars (GNS) decorated on adhesive tape.
• To demonstrate the practical application of the SERS patch for detecting analytes on nonplanar surfaces.

Main Methods:

• Fabrication of a flexible SERS patch by decorating multibranched gold nanostars (GNS) onto Scotch Tape.
• Correlation of experimental SERS measurements with theoretical finite element modeling (FEM) to optimize GNS structure.
• Detection of model analytes (rhodamine 6G and crystal violet) using the fabricated SERS patch.

Main Results:

• Gold nanostars with a 2.5 nm branch tip diameter (GNS-4) demonstrated the strongest SERS enhancement.
• The flexible SERS patch achieved a minimum detection limit of 1 pM for both rhodamine 6G and crystal violet.
• An ultra-high enhancement factor of 6.2 × 10^8 was calculated for the GNS-4 SERS patch.
• Good reproducibility was confirmed with a relative standard deviation (RSD) of 5.4% across 30 test spots.

Conclusions:

• The developed transparent and flexible SERS patch based on GNS-4 offers a versatile and low-cost platform for sensitive SERS sensing.
• This SERS substrate shows significant potential for real-world applications, particularly for detecting analytes on nonplanar surfaces.
• The cost-effective fabrication strategy and high sensitivity make this SERS patch suitable for point-of-care diagnostics.