English: The concept of simultaneous noninvasive sampling and monitoring of ISF and sweat. A) Depiction of wearable iontophoretic biosensor device on a printed tattoo platform for glucohol (glucose + alcohol) sensing on a human subject, along with wireless real-time transmission of the ISF glucose and sweat alcohol response. Scale bar: 7 mm. B) Image of the screen-printed glucohol biosensor coupled with wireless flexible printed circuit board. Scale bar: 7 mm. C) Schematic representation of iontophoretic operation. Induced generation of alcohol-containing sweat by iontophoretic delivery of pilocarpine at the anode with simultaneous reverse iontophoretic sampling of ISF glucose at the cathode. D) Schematic representation of glucohol biosensor, showing the “panda-like” electrode layout with iontophoretic gels and layered composition of the working electrodes. Scale bar: 7 mm. E) Schematic representation of biosensing operation. Amperometric detection of alcohol in the generated sweat and of glucose in the extracted ISF using AOx and GOx, respectively, along with measurement of the hydrogen peroxide product of these enzymatic reactions.