Abstract: An electrical circuit element, defined as “pixel”, can include at least one silicon nanowire open for contact with a medium for sensing; a metal electrode open for contact with said medium and used for feeding a high-frequency sinusoidal stimulation in impedance measurements and for sensing properties of said medium; implanted source and drain electrodes connected to said silicon nanowire and leaving the gate area and parts of said electrode open for contact with said medium; electrical metal contacts for connecting said pixel to an electrical circuit; and a reference electrode open for contact with said medium for creating a three-electrode-cell system and providing a constant gate potential in the circuit. Some embodiments provide a microelectronic sensor and wearable-patch sensor based on the array of these pixels. Also, some embodiments provide methods for performing DC readout, AC readout and a triple readout combining both DC and AC readouts and temperature sensing.