Wearable SERS Sensor Based on Omnidirectional Plasmonic Nanovoids Array with Ultra-High Sensitivity and Stability.

Area of Science:

• Materials Science
• Nanotechnology
• Spectroscopy

Background:

• Wearable sensors require high sensitivity and stability, which are challenging for current surface-enhanced Raman spectroscopy (SERS) technologies due to sensitivity to "hotspots" and excitation angle.
• Mechanical deformations in wearable devices can disrupt SERS activity, limiting practical applications.

Purpose of the Study:

• To develop a stable and highly sensitive wearable SERS sensor inspired by the compound eye of Xenos Peckii.
• To overcome the limitations of SERS sensitivity to "hotspots" distribution and excitation angle under mechanical stress.

Main Methods:

• Fabrication of an artificial plasmonic compound-eye (APC) structure by assembling metal nanoparticles into an interconnected frame.
• Creation of an omnidirectional plasmonic nanovoids array (OPNA) within the APC to enhance and stabilize "hotspots".
• Introduction of an asymmetry super-hydrophilic pattern for efficient analyte extraction from sweat.

Main Results:

• The OPNA structure provides broadband and omnidirectional enhancement of "hotspots", maintaining SERS activity integrity against mechanical deformations.
• The super-hydrophilic pattern enables spontaneous extraction and concentration of analytes from sweat.
• The developed sensor demonstrates high sensitivity and stability for wearable and in situ analysis.

Conclusions:

• The armored SERS sensor, inspired by insect compound eyes, offers a promising solution for stable and sensitive wearable sensing.
• This technology has significant potential for point-of-care diagnostics and real-time health monitoring.