A) Separation of 31, 44, and 50 nm large AuNPs in 20, 25, 30, 35, and 40 wt% PVP 10 000 viscosity gradient. B) Separation of five differently sized AuNPs in 5.8, 8.7, 11.8, 14.8, and 18.7 wt% PVP 40 000 viscosity gradient. Five NPs fractions are indicated by arrows. NPs sizes and viscosities of each gradient are the same as in Figure 1. C) Separation of three differently sized AuNPs in 11.8, 14.8, 18.7, 22.8, and 27.0 wt% PVP 40 000 viscosity gradient. NPs sizes and viscosities of each gradient are the same as in Figure 2A. In all images, gradients are built identical to the structure in the leftmost part of Figure 1A.