Stretchable gold fiber-based wearable electrochemical sensor toward pH monitoring

• Published in: Journal of materials chemistry. B, Materials for biology and medicine Vol. 8; no. 16; pp. 3655 - 366
• Main Authors: Wang, Ren, Zhai, Qingfeng, Zhao, Yunmeng, An, Tiance, Gong, Shu, Guo, Zhirui, Shi, QianQian, Yong, Zijun, Cheng, Wenlong
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 29.04.2020
• Subjects: Biosensing Techniques; Chemical sensors; Circuit design; Elastomers; Electrochemical Techniques; Electrochemistry; Electrodes; Fibers; Gold; Gold - chemistry; Homeostasis; Humans; Hydrogen ion concentration; Hydrogen ions; Ion concentration; Ions; Metabolism; Nanoparticles - chemistry; Nanotechnology; Nanowires; Particle Size; pH effects; pH sensors; Polyamines; Selectivity; Sensors; Silver - chemistry; Silver chloride; Silver Compounds - chemistry; Stretchability; Surface Properties; Sweat; Textiles; Wearable Electronic Devices; Wearable technology
• ISSN: 2050-750X; 2050-7518
• DOI: 10.1039/c9tb02477h

Sweat pH is a key health indicator related to metabolism and homeostasis level through hydrogen ion concentration in biological bio-fluid. Therefore, increasing research efforts have been directed to develop wearable pH sensors towards continuous non-invasive monitoring of sweat pH values in the out-of-hospital environments. Herein, we report a stretchable gold fiber-based electrochemical pH sensor based on our recently developed elastomer-bonded gold nanowire coating technology. The densely packed gold film offers superior strain-insensitive conductivity, high stretchability and large electrochemical active surface area (EASA). By electrodepositing polyamine (PANI) and Ag/AgCl onto the gold fibers, we could selectively detect the pH based on open circuit potentials in an ion-selective electrode design. The obtained fiber-based pH sensors feature a great sensitivity (60.6 mV per pH), high selectivity against cationic interference and high stretchability (up to 100% strain). One of the attributes for the fiber-based sensors is that they can be weaved into textiles, holding great potential for integration into everyday clothing for "unfeelable" personal health monitoring. A stretchable gold fiber-based wearable electrochemical pH two-electrodes sensing system for human health monitoring.