Flexible and washable self-powered biosensors based on textile bioelectrodes for sensing glucose in sweat

This study fabricated a flexible and washable self-powered biosensor—based on cellulose textiles—for sensing glucose in sweat. The sensor is integrated with T-shirts for practical use. The cellulose fiber was modified with carbon nanotubes and reduced oxide graphene to decrease its electron transfer resistance and ohmic resistance. Due to their low resistance, the bioelectrodes display high electrocatalytic efficiency of glucose oxidation and oxygen reduction. The biosensors are assembled by packaging the bioanodes and gel electrolytes together. The assembled biosensors have a low limit of detection (6.7 µM) and a wide linear range (0.02–0.5 mM). The great sensing performances are strongly associated with the location of bioanodes and biocathodes. The outer biocathode protects the central bioanode that comes from oxygen and ensures the structural integrity of the device during bending cycles. It also reduces the damage caused by the washing. The biosensor also exhibited selectivity, repeatability, and great stability in different pHs and during long-term storage. Finally, the average recoveries in real sweat are 104.9 to 106.0%. Thus, the flexible and washable self-powered biosensors have great potential for diabetes diagnosis at an early stage by sensing glucose in sweat.