A wearable graphene-based patch that allows for accurate non-invasive blood-sugar diabetes monitoring and painless drug delivery has been developed by researchers at The Institute for Basic Science (IBS) Center for Nanoparticle Research in South Korea.
The device uses a hybrid of gold-doped graphene and a serpentine-shape gold mesh to measure pH (blood acidity level) and temperature by measuring the amount of glucose in sweat.
Ref: A graphene-based electrochemical device with thermoresponsive microneedles for diabetes monitoring and therapy. Nature Nanotechnology (21 March 2016) | DOI: 10.1038/nnano.2016.38
Owing to its high carrier mobility, conductivity, flexibility and optical transparency, graphene is a versatile material in micro- and macroelectronics. However, the low density of electrochemically active defects in graphene synthesized by chemical vapour deposition limits its application in biosensing. Here, we show that graphene doped with gold and combined with a gold mesh has improved electrochemical activity over bare graphene, sufficient to form a wearable patch for sweat-based diabetes monitoring and feedback therapy. The stretchable device features a serpentine bilayer of gold mesh and gold-doped graphene that forms an efficient electrochemical interface for the stable transfer of electrical signals. The patch consists of a heater, temperature, humidity, glucose and pH sensors and polymeric microneedles that can be thermally activated to deliver drugs transcutaneously. We show that the patch can be thermally actuated to deliver Metformin and reduce blood glucose levels in diabetic mice.