The invention relates to a sensor (1) comprising: a substrate layer (100) a GaN/AlGaN hetero-junction structure (105, 110) configured so as to form a 2DEG channel (120) within said structure and ohmic contacts (115) connected to electrical metallizations (125) and to the 2DEG channel wherein the GaN/AlGaN hetero-junction structure (105, 110) has a recessed area between the ohmic contacts (115) and a dielectric layer (130) on top of the sensor. The invention also relates to a device for ECG sensing, a use of a sensor for ECG sensing and a method for ECG detection.
