Figure 5.

The color change in paper-based sensors can be quantified through the analysis of a picture taken via smartphone. Reproduced with permission from [91]. An overview of the paper-based sensor that was used to detect glucose and lactate. (a) Two detection zones and the sample zone are contained in the top layer. The bottom layer contains a fluidic channel, and both of these layers are connected using double-sized adhesive tape. (b) The process of wax-printing used to construct the sensor. (c) The anterior and posterior sides of the sensor.