Wearable Potentiometric Chloride Sweat Sensor: The Critical Role of the Salt Bridge

• Published in: Analytical chemistry (Washington) Vol. 88; no. 24; pp. 12241 - 12247
• Main Authors: Choi, Dong-Hoon, Kim, Jin Seob, Cutting, Garry R, Searson, Peter C
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 20.12.2016
• Subjects: Balancing; Biomarkers; Body fluids; Chlorides; cystic fibrosis; Electrolytes; exercise; geometry; metabolism; Salt; Sensors; Sweat; Time measurement; Wearable
• ISSN: 0003-2700; 1520-6882; 1520-6882
• DOI: 10.1021/acs.analchem.6b03391

The components of sweat provide an array of potential biomarkers for health and disease. Sweat chloride is of interest as a biomarker for cystic fibrosis, electrolyte metabolism disorders, electrolyte balance, and electrolyte loss during exercise. Developing wearable sensors for biomarkers in sweat is a major technological challenge. Potentiometric sensors provide a relatively simple technology for on-body sweat chloride measurement, however, equilibration between reference and test solutions has limited the time over which accurate measurements can be made. Here, we report on a wearable potentiometric chloride sweat sensor. We performed parametric studies to show how the salt bridge geometry determines equilibration between the reference and test solutions. From these results, we show a sweat chloride sensor can be designed to provide accurate measurements over extended times. We then performed on-body tests on healthy subjects while exercising to establish the feasibility of using this technology as a wearable device.