Fig 1: (a) Comparison of experimental and COMSOL simulation results for Mean Gray Value (MGV) at different CD spin rates (rpm). The blue bars represent experimental MGV for the biotin–streptavidin (Bt–Strept) interaction, while the orange bars correspond to the simulated MGV. Inset images illustrate analyte flow at several disc spin rates. The saturation (Sat) condition represents the maximum possible signal obtained when the NC membrane is fully immersed in analyte for 4 min. (b) Damköhler number (Da) variation with CD spin rate for fast- and slow-reacting systems. The blue bars represent Da values for fast-reacting biotin–streptavidin (Bt–Strept), while the orange line represents Da values for the slower-reacting CD79 antigen–antibody system. The Da numbers for Bt–Strept are indicated on the left vertical axis; for CD79b, they are on the right vertical axis to facilitate legibility.