Figure 2.

Three typical force–displacement curves of AFM are shown to demonstrate the interaction events between the tip and the substrate surface. ac The force–displacement curves when there were either no interactions (bare tip/rat anti-human IgG), specific interactions (human IgG/rat anti-human IgG), or only non-specific interactions (blocking experiment)

Lv et al. Nanoscale Research Letters 2010 5:1032-1038   doi:10.1007/s11671-010-9598-x