Figure 4.

Surface diffusion versus direct binding. Shown are binding rates $k_{\text{on}}$ (green line) and $k_{\text{surface}\text{diffusion}}$ (blue dash-dotted line) as a function of the surface-state cut-off, $d_{\text{surface}/\text{bulk}}$. For comparison, $k_{\text{bulk}\to \text{surface}}$ from the simple Smoluchowski model (yellow dashed line) and a Smoluchowski model including transient surface-binding states (orange dashed line), as well as the measured on-rate coefficient (magenta dash-dotted line), are also shown. To see this figure in color, go online.