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A Wearable Electrochemical Platform for Noninvasive Simultaneous Monitoring of Ca2+ and pH
journal contribution
posted on 2016-07-05, 00:00 authored by Hnin Yin
Yin Nyein, Wei Gao, Ziba Shahpar, Sam Emaminejad, Samyuktha Challa, Kevin Chen, Hossain
M. Fahad, Li-Chia Tai, Hiroki Ota, Ronald W. Davis, Ali JaveyHomeostasis
of ionized calcium in biofluids is critical for human
biological functions and organ systems. Measurement of ionized calcium
for clinical applications is not easily accessible due to its strict
procedures and dependence on pH. pH balance in body fluids greatly
affects metabolic reactions and biological transport systems. Here,
we demonstrate a wearable electrochemical device for continuous monitoring
of ionized calcium and pH of body fluids using a disposable and flexible
array of Ca2+ and pH sensors that interfaces with a flexible
printed circuit board. This platform enables real-time quantitative
analysis of these sensing elements in body fluids such as sweat, urine,
and tears. Accuracy of Ca2+ concentration and pH measured
by the wearable sensors is validated through inductively coupled plasma-mass
spectrometry technique and a commercial pH meter, respectively. Our
results show that the wearable sensors have high repeatability and
selectivity to the target ions. Real-time on-body assessment of sweat
is also performed, and our results indicate that calcium concentration
increases with decreasing pH. This platform can be used in noninvasive
continuous analysis of ionized calcium and pH in body fluids for disease
diagnosis such as primary hyperparathyroidism and kidney stones.