Figure 4
PeakForce QNM analysis of AuNP-immobilized surfaces. (a, b) Topographic AFM images of 20 nm of AuNPs immobilized on aminated surface and DOPA-functionalized surface, respectively. (c, d) Adhesion images of the samples show relative adhesion interaction between the bare Si AFM tip and AuNPs or other regions outside the AuNPs. All scale bars are 200 nm. The dashed line is a depiction of AFM stylus trajectory. (e, f) AFM deformation images show a larger deformation change near the edge than at the center of the nanoparticles. (g, h) Schematic diagram of the geometric design depicted AuNPs immobilized on the substrates functionalized with amino group and DOPA molecules, respectively. The terms wtopology and htopology indicate the measured width and height, respectively, of the AuNPs in the aspect of topology (a, b).