posted on 2023-12-05, 20:25authored byYu Han, Xiaohui Fang, Hanlin Li, Lei Zha, Jinxin Guo, Xinping Zhang
Wearable sweat sensors provide real-time monitoring of
biomarkers,
enabling individuals to gain
real-time insight into their health status. Current sensors primarily
rely on electrochemical mechanisms, limiting their capacity for the
concurrent detection of multiple analytes. Surface-enhanced Raman
scattering spectroscopy offers an alternative approach by providing
molecular fingerprint information to facilitate the identification
of intricate analytes. In this study, we combine a wearable Janus
fabric for efficient sweat collection and a grapefruit optical fiber
embedded with Ag nanoparticles as a sensitive SERS probe. The Janus
fabric features a superhydrophobic side in contact with the skin and
patterned superhydrophilic regions on the opposite surface, facilitating
the unidirectional flow of sweat toward these hydrophilic zones. Grapefruit
optical fibers feature sharp tips with the ability to penetrate transparent
dressings. Its microchannels extract sweat through capillary force,
and nanoliter-scale volumes of sweat are sufficient to completely
fill them. The Raman signal of sweat components is greatly enhanced
by the plasmonic hot spots and accumulates along the fiber length.
We demonstrate sensitive detection of sodium lactate and urea in sweat
with a detection limit much lower than the physiological concentration
levels. Moreover, the platform shows its capability for multicomponent
detection and extends to the analysis of real human sweat.