Flexible glucose sensor using CVD-grown graphene-based field effect transistor.

A flexible glucose sensor using a CVD-grown graphene-based field-effect-transistor (FET) is demonstrated. The CVD-grown graphene was functionalized with linker molecules in order to immobilize the enzymes that induce the catalytic response of glucose. Polyethylene terephthalate (PET) was employed as the substrate material to realize a flexible sensor. The fabricated graphene-based FET sensor showed ambipolar transfer characteristics. Through measurements of the Dirac point shift and differential drain-source current, the fabricated FET sensor could detect glucose levels in the range of 3.3-10.9 mM, which mostly covers the reference range of medical examination or screen test for diabetes diagnostic. This CVD-grown graphene-based FET sensor, which provides excellent fitting to a model curve even when deformed, high resolution, and continuous real-time monitoring, holds great promise, especially for portable, wearable, and implantable glucose level monitoring applications.