Fig. 1.

ROS sensor fabrication, characterization, and results. a Inkjet printing of ROS sensor pattern and sintering process b The real image of the printed sensor pattern, c CV response using potassium ferricyanide (K₄ [Fe(CN)₆]) and KCl. d calibration curve using different ROS solution at 0.65 V obtained from chrono-amperometry; e ROS sensor data of liver fibrosis-on-chip model with fibronectin as ECM. Real-time H₂O₂ concentration was monitored for 14,000 s for every second. There was no significant release of H₂O₂ in the fibronectin based liver fibrosis-on-chip model before the addition of the fibrosis-inducing TGF-β1 stimulation. The addition of TGF-β1 resulted in a positive output signal, and a continuous release of H₂O₂ was observed