A Wearable Electrochemical Sensor for the Real-Time Measurement of Sweat Sodium Concentration

We report a new method for the real-time quantitative analysis of sodium in human sweat,consolidating sweat collection and analysis in a single, integrated, wearable platform. This temporaldata opens up new possibilities in the study of human physiology, broadly applicable from assessinghigh performance athletes to monitoring Cystic Fibrosis (CF) sufferers. Our compact Sodium Sensor Belt (SSB) consists of a sodium selective Ion Selective Electrode (ISE) integrated into a platform that can be interfaced with the human body during exercise. No skin cleaning regime or sweat storagetechnology is required as the sweat is continually wicked from the skin to a sensing surface and fromthere to a storage area viaa fabric pump. Our results suggest that after an initial equilibration period,a steady-state sodium plateau concentration was reached. Atomic Absorption Spectroscopy (AAS) wasused as a reference method, and this has confirmed the accuracy of the new continuous monitoring approach. The steady-state concentrations observed were found to fall within ranges previously foundin the literature, which further validates the approach