A conducting polymer PEDOT:PSS hydrogel based wearable sensor for accurate uric acid detection in human sweat

Noninvasive wearable sensors present key information about targeting epidermally retrievable biofluids in human health monitoring. Tracking circulating uric acid (UA) in human sweat performs a simple and prompt way for reducing risk of gout and hyperuricemia. Herein, we propose a wearable microfluidic-based electrochemical sensor via incorporating conducting polymer PEDOT:PSS hydrogel towards accurate and sensitive detection of UA in sweat. The microfluidic device validly realizes the capture for sweat in real-time, and the conducting PEDOT:PSS hydrogel with large surface area plays multiple roles in this wearable sensor for UA detecting, electrolyte storing, and flexibility enhancing. The prepared flexible sensor shows an ultrahigh sensitivity of 0.875 µA µM−1 cm−2 and a low limit of detection (LOD) down to 1.2 μM (S/N = 3). Furthermore, it can detect UA levels in real human sweat samples collected from volunteers before and after purine-rich diets, and the results are highly correlated with those measured by the standard enzyme linked immunosorbent assay (ELISA). This PEDOT:PSS hydrogel based flexible sensor, together with the sweat-collecting microfluidic device, is believed to be promising for the construction of high performance wearable sensors to monitor biomarkers, metabolites and nutrients.