An integrated flexible and reusable graphene field effect transistor nanosensor for monitoring glucose

Diabetes is a chronic metabolic disease that has effect on blood sugar level and affects millions of people. We present an integrated flexible and reusable graphene-based field effect transistor (GFET) nanosensor for the detection of glucose using pyrene-1-boronic acid (PBA) as the receptor. The nanosensor fabricated on the polyimide performs GFET-based rapid transduction of the glucose-PBA binding, thereby potentially allowing the detection of glucose that are sampled reliably from human bodily fluids (e.g., sweat) in wearable sensing applications. Due to the reversible binding interaction between PBA and glucose, reusability of our nanosensor can be realized by exposing graphene surface to acidic solution. In characterizing the stability and reusability of the nanosensor for wearable applications, we investigated the effects of substrate bending, multiple reuse and long-time storage on the equilibrium dissociation constant between the PBA and glucose. Results show that bending, multiple reuse (over 10 times) and long-time storage has negligible effect on the sensing performance. The detection of glucose with a limit of detection (LOD) of 0.15 μM and a dynamic range of 0.05–100 mM, which covers the reference scope of physical examination or screening of diabetes. Hence, our flexible GFET nanosensor is promising for wearable and reusable biosensing applications.