Figure 3: Off-chip TF measurement using the developed EC bead-based immunosensing approach.

(a) Amperometry measurement of the EC sensor at −100 mV for different standard TF concentrations obtained by 1:4 serial dilutions. (b) EC calibration curve for TF obtained from standard TF solutions (0–16,000 ng/mL), insert is linear regression. (c) The selectivity of the developed EC immunosensor using MBs with and without coupled TF primary antibody. (d) Production rate of TF in HepG2 bioreactor samples measured by ELISA and the developed electrochemical sensor. Data are representative of three independent experiments (ns = not significant; *P < 0.05; ***P < 0.001).