fig2

Figure 2. Wearable SERS devices integrated with microfluid systems or sweat extraction systems. (A) A photo of an integrated paperfluidic device with six plasmonic sensors. (B) A photo of crumbled paperfluidic device. (C) A photo of wearable paperfluidic SERS device during the test with a portable Raman spectrometer. (D) Comparison of SERS spectra collected with benchtop and portable spectrometers. (E) Schematic structure of wearable SERS devices with sweat extraction system. (F) Schematic illustration showing the working principle of the sweat extraction system. (G) Evolution of the characteristic Raman peak of nicotine under different conditions. (H) A photo of the integrated SERS sensor array connected to a flexible stimulation circuit, which is mounted on human skin (I) A photo of the custom-developed control app for electrical stimulation. (J) Simultaneous tracking of pH and nicotine concentration. (A-D) are adapted with permission. Copyright 2022, AAAS. (E-J) are adapted with permission. Copyright 2022, AAAS.