Figure 4.

Detections of glucose and body temperature ex vivo using colorimetric dermal tattoo biosensors. A) Detection of glucose ex vivo, in the range of increasing glucose concentration (≈0–10 mm) (upper row) and decreasing glucose concentration (≈10–0 mm) (lower row). B) Detection of temperature ex vivo, during heating (≈36–39 °C) (upper row) and cooling (≈39–36 °C) (lower row). C,D) The Hue values extracted from the images in (A) and (B) as a function of glucose concentration (C) and temperature (D).