Flexible, stretchable, and single-molecule-sensitive SERS-active sensor for wearable biosensing applications

Area of Science:

• Biomedical Technology
• Materials Science
• Nanotechnology

Background:

• Wearable sensors are revolutionizing remote patient monitoring and personalized medicine.
• Plasmonic metasurfaces enhance Raman scattering signals, showing promise for wearable sensor applications.
• Developing flexible, sensitive, and easily fabricated metasurfaces remains a significant challenge.

Purpose of the Study:

• To propose a novel wearable device: a flexible, stretchable, and single-molecule-sensitive surface-enhanced Raman scattering (SERS)-active sensor.
• To address the long-standing need for high-performance, adaptable metasurfaces in biosensing.
• To demonstrate a viable platform for advanced personalized medicine and remote health monitoring.

Main Methods:

• Fabrication of a SERS-active sensor utilizing a polydimethylsiloxane (PDMS) substrate for flexibility.
• Characterization of the sensor's performance, including its enhancement factor, scattering to absorption ratio, and hotspot volume.
• Numerical simulations to assess the sensor's reliability under mechanical strain (bending and stretching).

Main Results:

• Achieved an unprecedented SERS enhancement factor of approximately 10¹¹.
• Demonstrated a high scattering to absorption ratio (∼2.5) and a large hotspot volume (40 nm × 40 nm × 5 nm).
• Confirmed reliable SERS performance under bending (up to 100°) and stretching (up to 50%).

Conclusions:

• The proposed flexible and stretchable SERS sensor offers exceptional sensitivity and performance.
• Its ease of fabrication and adaptability make it a promising candidate for wearable diagnostic devices.
• This technology paves the way for advancements in personalized medicine and remote patient monitoring.