Figure 6.

SPE cards combined with paper elements: (A) Picture of the paper-based device developed by Noiphung et al. for whole blood separation and glucose determination. Reprinted from [79], Copyright (2013), with permission from Elsevier. (B) Schematic representation of the separation, visualization and measurement steps in the paper-based devices developed by Primpray et al. for the determination of steroids. Reprinted from [92], Copyright (2019), with permission from Elsevier. (C) Schematic representation of the paper-based system for in-situ generation of gold nanoparticles and further analysis of arsenic developed by Nuñez-Bajo et al. Reprinted with permission from [105]. Copyright (2017) American Chemical Society. (D) Schematic diagram of the multilayer platform developed by Yang et al. for pesticide detection. Reprinted with permission from [95], Copyright (2020) Wiley Periodicals LLC. Fully-integrated paper-based electrochemical devices: (E) Evaluation of the robustness of the paper-based device developed by Cinti et al. for the detection of chloride ions, after 100 repeated bending (red) and twisting (green) tests. Reprinted from [114], Copyright (2017), with permission from Elsevier. (F) Schematic diagrams of the configuration of the origami device developed by Arduini et al. for the detection of pesticides. Reprinted from [115], copyright (2018), with permission from Elsevier.