Graphene (Gr) is currently one of the most appealing materials as conductive transparent electrode for flexible electronics, thanks to its bendability/stretchability accompanied by small variations of the electrical properties after mechanical deformations. In addition, the field-effect tunable carrier density combined to a high mobility and saturation velocity make it an excellent channel material for field-effect transistors (FETs) even on flexible substrates. By proper design of the device structure (channel length, top- or back-gate configuration), Gr-FETs can be used for high-frequency (RF) electronics or for high-sensitivity chemical, biological, and environmental sensors exploiting transconductance variations in response to the chemi/physisorption of molecular species on Gr channel. In particular, miniaturized and flexible Gr-FET sensors can represent a strong advance with respect to current sensors technology …