Cotton thread-based wearable sensor for non-invasive simultaneous diagnosis of diabetes and kidney failure

Abstract

Thread has become a promising substrate for non-invasive wearable sensor. Herein, we create a modified cotton thread-based colorimetric sensor for non-invasive and simultaneous detection of glucose and urea excreted from human sweat. Cellulose nanofiber/chitosan-graphene oxide was selected to modify the cotton thread surfaces for enhancing of enzymatic immobilization efficiency and sensor performance. The modified thread surfaces were characterized by scanning electron microscopy and X-ray photoelectron spectroscopy. This sensing platform exhibits a linear range of 0.1–3 mM with a detection limit of 0.1 mM for glucose and a linear range of 30–180 mM with a detection limit of 30 mM for urea. Interestingly, this colorimetric sensor can determine the cut-off levels for both glucose (0.3 mM) and urea (65 mM) in human sweat, thus it can effectively distinguish between normal and abnormal people. Due to the thread flexibility nature, this sensor can be readily integrated with the clothes and accessories for real-time and continuous monitoring of diabetes and kidney failure from the wearer’s sweat. This platform might open a new road for blood-free diagnosis in healthcare applications.