Abstract
This paper reports on the development of a flexible-wearable potentiometric sensor for real-time monitoring of sodium ion (Na(+)), potassium ion (K(+)), and pH in human sweat. Na(0.44)MnO(2), polyaniline, and K(2)Co[Fe(CN)(6)] were used as sensing materials for Na(+), H(+) and K(+) monitoring, respectively. The simultaneous potentiometric Na(+), K(+), and pH sensing were carried out by the developed sensor, which enables signal collection and transmission in real-time to the smartphone via a Wi-Fi access point. Then, the potentiometric responses were evaluated by a designed android application. Na(+), K(+), and pH sensors illustrated high sensitivity (59.7 ± 0.8 mV/decade for Na(+), 57.8 ± 0.9 mV/decade for K(+), and 54.7 ± 0.6 mV/pH for pH), excellent stability, and good batch-to-batch reproducibility. The results of on-body experiments demonstrated that the proposed platform is capable of real-time monitoring of the investigated ions.