Figure 4: Characterization of on-chip MBs loading.

(a) Illustration of trapped MBs in the reaction chamber. Circular shadows in the background are bubble trap microposts embedded on the top surface of the reaction chamber. (b) On-chip capture efficiency of loaded MBs at different flow rates. (c) Sensitivity of the on-chip immunoassay at different numbers of immobilized beads for detection of standard TF concentration in the linear range of the assay (10–4,000 ng/mL). Data are representative of three independent experiments (ns = not significant; *P < 0.05).