Fluid Domain-Limited Ag Nanoparticles on Janus Fabric for SERS-Based Label-Free Sweat Detection

Flexible wearable biosensors enable dynamic tracking of biomarkers in sweat through noninvasive sampling. Surface-enhanced Raman spectroscopy (SERS) utilizes the “fingerprint” vibrations of molecular vibration spectra to simultaneously analyze multiple substances, facilitating the identification of complex analytes. In this study, we integrated a Janus fabric with efficient wearable moisture management properties with silver (Ag) nanoparticles to develop an SERS sensor for human sweat detection. The hydrophobic side of the Janus fabric was designed to contact the skin, while hydrophobic patterns were printed on the opposite side to enable the efficient enrichment of target molecules. Rapid sweat transport was achieved through a combination of a hydrophilic–hydrophobic interfacial design. The moisture management capability and SERS enhancement mechanism of the platform were further explained through simulation. Moreover, the platform demonstrated the successful detection of real human sweat samples. This work is expected not only to provide a novel approach for the fabrication and preparation of the SERS active fabric with excellent performance but also to promote the theoretical basis and technical support for the research of textile on rapid detection in highly diluted biochemical samples.