Flexible Electrochemical Sensor for Interleukin-6: Toward Wearable Cytokine Monitoring

Abstract

The detection of cytokines, key proteins involved in the immune system signaling, is of extreme importance for health monitoring. Among the various cytokines, interleukin-6 (IL-6), is particularly interesting to monitor, also considering that sweat IL-6 levels show a significant correlation with blood levels, in the range of pg/mL. Despite its importance, sensitive and wearable detection of IL-6 in sweat is still lagging behind. In this work, we fabricated and characterized a flexible screen-printed carbon-based three-electrode electrochemical sensor for IL-6 detection. The planar electrochemical sensor was first modified with gold nanoparticles and then biofunctionalized with thiolated aptamers. The characterization via electrochemical impedance spectroscopy demonstrated selective IL-6 detection in the range from 0.2 pg/mL to 20 pg/mL in artificial sweat, perfectly covering the physiological range of interest. Our results suggest the potential integration