Abstract
Increased development of wearable sensors for physiological monitoring has spurred complementary interest in the detection of biochemical indicators of health and performance. We report a wearable sensor system for non-invasive detection of excreted human biomarkers in sweat. The system consists of a thin, flexible, kapton patch (2.5 × 7.5 cm) that can be coated with adhesive and affixed to the skin. The system can be controlled by a cell phone via a near-field communications protocol, charged wirelessly, and the data can be downloaded and displayed in a smart phone app. The system is designed such that the sensing element plugs into a low-profile socket, and can easily be removed and replaced as needed due to saturation or aging effects. As a demonstration case, we examined using an organic electrochemical transistor (OECT) within this system to monitor lactate concentration. Several different methods for optimizing the sensor performance were compared, including altering electrode materials, employing various immobilization techniques, and tailoring operating voltages. Resulting functional response of the lactate oxidase enzyme was compared as a function of the sensor variables. The OECT sensor was shown to have high sensitivity to lactate, however the sensing range is limited to lactate concentrations below approximately 1 mM.
Highlights
Wearable sensors have emerged as a major area of growth for consumer, sports, and military applications as they offer unique possibilities for in-situ, real-time, and non-invasive monitoring of health and performance
organic electrochemical transistor (OECT) are compatible with simple, inexpensive fabrication techniques that are well-suited for flexible electronics
OECTs can be applied as sensors for chemical reactions that result in small changes in the gate potential
Summary
Wearable sensors have emerged as a major area of growth for consumer, sports, and military applications as they offer unique possibilities for in-situ, real-time, and non-invasive monitoring of health and performance. Despite the exponential progress in the field, several key challenges remain, as discussed in detailed reviews[9,18,19,20] Two of these challenges include the sensor’s power source and the operation of the sensing element. OECTs have extremely high transconductance and can serve as label-free sensors for enzymatic and immunoassay detection methods[24,25,26,27,28,29], making them potential universal transduction platform candidates for all types of sweat analytes. We use lactate as the analyte of choice to demonstrate proof of concept[30,31,32,33], but the sensor platform can be expanded to multiple analytes This system could provide significant advantages for health and performance monitoring in low-resource settings
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
