Figure 2.

Photograph and schematic of the microfluidic system

Set-up components are marked by dashed line: four reagent stock tubes, four pumps (blue dashed line), PDMS cubic exchanger (fluid exchanger made of PDMS) (orange dashed line), 200 μL pipette tip with a stopper installing the microfibrous reactor (red dashed line), black 3D-printed resin cassette enclosing RGB phototransistor (blackish green dashed line), signal output (gray dashed line). The schematic of the competitive ELISA via the automatic microfluidic system is also shown in the green box. In the competitive procedure of HRP-cortisol/cortisol incubation, and TMB incubation, the flow direction in the pipette chamber is switched for mixing it up and down (255 μL/min). A colored arrow marked the flow direction. See also Figures S4–S7.