Wearable Potentiometric Sensor Based on Na<sub>0.44</sub>MnO<sub>2</sub> for Non-invasive Monitoring of Sodium Ions in Sweat
Arash Ghoorchian, Mahdie Kamalabadi, Mahdi Moradi, Tayyebeh Madrakian, Abbas Afkhami, Hasan Bagheri, Mazaher Ahmadi, Hosein Khoshsafar
Abstract
Here, we present a wearable potentiometric ion sensor for real-time monitoring of sodium ions (Na+) in human sweat samples using Na0.44MnO2 as the sensing material. Na0.44MnO2 is an attractive material for developing wearable electrochemical sensors due to its good Na+ incorporation ability, electrical conductivity, stability, and low fabrication cost. In the first step, the analytical performance of the electrode prepared using Na0.44MnO2 is presented. Then, a miniaturized potentiometric cell integrated into a wearable substrate is developed, which reveals a Nernstian response (58 mV dec–1). We achieved the detection of Na+ in the linear ranges of 0.21–24.54 mmol L–1, which is well within the physiological range of Na+. Finally, for on-body sweat analysis, the potentiometric sensor is fully integrated into a headband textile. This platform can be employed for non-invasive analysis of Na+ in human sweat for healthcare and disease diagnosis.