An on-body wearable bio-fluid collection and sensing device including an interface or interface surface comprising at least one biocompatible material for contacting a bodily part; at least one inlet for receiving the bio-fluid, at least one outlet for evacuating the bio-fluid, a plurality of semiconductor sensors configured to analyze the received bio-fluid, at least one reference electrode for biasing a bio-fluid gate of at least one of the semiconductor sensors, and at least one micro-fluidic or nano-fluidic channel in fluid communication with the at least one inlet, the at least one outlet and the at least one reference electrode; the at least one micro-fluidic or nano-fluidic channel includes the plurality of semiconductor sensors.