A scientific team from the Center for Nanoparticle Research at the Institute for Basic Science (IBS) in South Korea has created a wearable, graphene-based patch that uses human sweat for diabetes monitoring and feedback therapy. The researchers improved the device’s detecting abilities by integrating electrochemically active, soft functional metals on a hybrid of gold-doped graphene and a serpentine-shape gold mesh. The enzyme-based glucose sensor is triggered by pH and temperature, and the device’s pH and temperature monitoring functions enable systematic corrections of sweat glucose measurements.
The IBS device offers non-invasive, painless, and stress-free monitoring of markers of diabetes using multifunctional, wearable devices, reducing visits to doctors and pharmacies.
“Our wearable graphene-based device is capable of not only sweat-based glucose and pH monitoring but also controlled transcutaneous drug delivery through temperature-responsive microneedles,” says Kim Dae-Hyeong, a scientist from the Center for Nanoparticle Research. “Precise measurement of sweat glucose concentrations are used to estimate the levels of glucose in the blood of a patient. The device retains its original sensitivity after multiple uses, thereby allowing for multiple treatments. The connection of the device to a portable/wireless power supply and data transmission unit enables the point-of-care treatment of diabetes.”
The patch is applied to the skin with sweat-based glucose monitoring beginning when sweat is generated, and the humidity sensor monitors the increase in relative humidity (RH). It takes about 15 minutes for the sweat-uptake layer of the patch to collect sweat and reach RH higher than 80%, initiating glucose and pH measurements. If abnormally high levels of glucose are detected, a drug is released into a patient’s bloodstream via microneedles.
The scientific team also demonstrated the therapeutic effects by experimenting on diabetic mice. Treatment began by applying the device near the abdomen of the diabetic mouse, and then microneedles pierced the skin and released Metformin, an insulin-regulating drug, into the bloodstream. The group treated with microneedles showed a significant suppression of blood glucose concentrations with respect to control groups.
“One can easily replace the used microneedles with new ones. Treatment with Metformin through the skin is more efficient than that through the digestive system because the drug is directly introduced into metabolic circulation through the skin,” says Dae-Hyeong. “These advances using nanomaterials and devices provide new opportunities for the treatment of chronic diseases like diabetes.”
IBS Center for Nanoparticle Research