fig7

Figure 7. Schematic and performance of a wearable intelligent sweat sensing platform based on SERS. (A) Illustration of the SERS detection mechanism on the plasmonic paperfluidic substrate; (B) Exploded view of the multilayer device structure and skin interface; (C) Smartphone interface displaying the calculated sweat volume and pH value; (D) SERS spectra of UA at concentrations ranging from 10^-3 to 10^-7 M; (E) Calibration curve showing the polynomial fit of SERS intensity at 637 cm^-1 vs. UA concentration; (F) SERS spectra of UA compared with various coexisting analytes, demonstrating spectral selectivity; (G) SERS spectra of UA in sweat across different pH levels; (H) SERS spectra of UA with and without a pH indicator; (I) SERS spectra of UA in different environments, including PBS, sweat, and water. Reprinted with permission from^[113], Copyright 2024, Royal Society of Chemistry. SERS: Surface-enhanced Raman spectroscopy; UA: uric acid; PBS: phosphate buffered saline.