A Flexible Enzymatic Sensor for Glucose and Uric Acid Detection in Sweat

Abstract

This study developed a high-performance, flexible electrochemical sensor for detecting glucose and uric acid in sweat. The sensor, based on a screen-printed carbon electrode (SPE), incorporates gold and Prussian blue (PB) as electron mediators. Glucose oxidase (GOx) and uric acid oxidase are then drop-cast onto the modified electrode to complete sensor fabrication. Key performance factors, including enzyme amounts and binder type, were optimized. The flexible glucose sensor showed a linear range of 0–10 µM with a maximum sensitivity of 579.06 µA/mM cm^–2, and 10–100 µM with 32.37 µA/mM cm^–2 sensitivity. The flexible uric acid sensor exhibited a linear range of 4–30 µM with a maximum sensitivity of 341.13 µA/mM cm^–2. Both sensors showed good selectivity and minimal interference from common substances like ascorbic acid, KCl, and NaCl, ensuring reliability in complex environments. In practical tests with real sweat samples, both sensors displayed stable performance, with measured glucose and uric acid concentrations closely matching theoretical values, confirming their potential for accurate detection. A smartphone app displays test results, enabling users to monitor their health without needing prior sensor knowledge.