Sweat Sensor Based on Wearable Janus Textiles for Sweat Collection and Microstructured Optical Fiber for Surface-Enhanced Raman Scattering Analysis

Flexible Wearable Plasmonic Paper-Based Microfluidics with Expandable Channel and Adjustable Flow Rate for Portable Surface-Enhanced Raman Scattering Sweat Sensing

“…SERS utilizes the surface plasmonic resonance effect of nanostructures to amplify the fingerprint signals of analytes by several orders of magnitude, allowing for highly sensitive detection and quantitative analysis even down to the single-molecule level. , The integration of SERS with technologies such as microfluidics, , optical fibers, ,, and microchips, combined with wearable technology, has sparked extensive research in biomedical applications and human biomarker detection. Although SERS wearable technology has faced significant challenges in integrating lasers and spectrometers into wearable devices, it has developed its versatility to include automated sweat capture, quantification of sweat rate, rate of sweat loss, analysis and quantification of multiple constituents, and more. , SERS has been applied in various fields including biomolecular detection, drug identification, physiological parameter monitoring, and disease diagnosis. − The composition of sweat is closely related to the physiological state of the human body, making it an emerging field for noninvasive detection. For example, UA is an important biomarker whose concentration in sweat and serum is positively correlated with the diseases such as gout, diabetes, and hyperuricemia. − Under normal pH condition, the concentration of UA in sweat should be lower than 40 μM. , While abnormal pH value of sweat is closely related to metabolic alkalosis and cystic fibrosis. , Currently, only a few studies have reported the implementation of wearable in situ sweat SERS sensing using portable Raman spectroscopy techniques. ,, …”

Unlocking the Potential of Wearable Sensors in Healthcare and Beyond

“…In another example, using surface-enhanced Raman scattering (SERS) substrates, Liu et al have recently developed MXene–OH–Au membranes as wearable sensors for nicotine, methotrexate, nikethamide, and 6-acetylmorphine in sweat . Alternatively, using a Janus textile to extract sweat using capillary forces and promote the unidirectional flow of sweat, Zhang and co-workers implemented a grapefruit optical fiber with embedded Ag nanoparticles to achieve physiologically relevant detection of sodium lactate and urea in sweat . Taken together, these advances illustrate continued potential for sweat-based biosensors to provide biomedically relevant information.…”