Wearable epidermal sensors with surface-enhanced Raman spectroscopy for personalized health

Wearable epidermal sensors can realize real-time, minimally invasive or noninvasive monitoring of biomarkers such as those found in sweat, interstitial fluid (ISF), and wound exudate. Conventional electrochemical and colorimetric sensing techniques face challenges in achieving reliable multiplexed detection. Surface-enhanced Raman spectroscopy (SERS) can offer molecular specificity for detecting trace biomarkers. This review examines the use of SERS in epidermal sensors, with a focus on material design, substrate functionalization, and biofluid sampling strategies. We discuss opportunities for future development in device structural design, the use of plasmonic materials, multi-functional integration, and AI-driven diagnostics.