Fig. 2.

Onset of clustered-charge behavior, enabling specific adsorption of α-lactalbumin, via (A) synthetic peptide oligomer length and (B) increased grafting density of monoargininamide. The number of specific adsorption sites (per 160 µm², 60 s) is reported on each plot with graphic representations of the ligands overlaid. (A) Peptide oligomer length on the functionalized agarose was varied. The preparation charge concentration (215 µM) was the same for all samples during substrate modification. (B) Monoargininamide density as a percent increase from the benchmark 215 µM shown in Fig. 1I was varied. Representative superresolution pseudo images are shown for each corresponding color-coded point. (Scale bar: 1 µm.) Dashed lines are shown as guide for the eye. Error bars represent the SD from five different 62-s trials taken from three different areas of the same sample.