Development of wearable, screen-printable conductive polymer biosensors on flexible and textile substrates

Wearable biosensors have great potential for real-time diagnostics, but have been encumbered by costly fabrication processes, rigid materials, and inadequate sensitivity for physiological ranges. Sweat has hitherto been an understudied sample for measurement of components like pH and lactate, which can provide meaningful guidance for wound healing, eczema, and sports medicine applications. This thesis presents the development of a flexible, textile-based, screen-printed electrode system for biosensing applications. Furthermore, a flexible, pH-sensitive composite for textile substrates is developed by mixing polyaniline with dodecylbenzene sulfonic acid and textile screen-printing ink. The optimized composite's pH response is compared to electropolymerized and drop-cast polyaniline sensors via open circuit potential measurements. A linear response is observed for all sensors between pH 3-10, with the composite demonstrating sufficient response time and a sensitivity better than -20 mV/pH, exceeding existing flexible screen-printed pH sensors. Investigations into a potentiometric, non-enzymatic lactate sensor using polyaminophenylboronic acid are also discussed.