AFM study of organic ligand packing on gold for nanoparticle drug delivery applications

Gold nanoparticles (AuNPs) functionalized with polyethylene glycol (PEG) and peptide ligands are promising drug delivery vectors for use in cancer therapy. However, to control the interaction of blood proteins specific cell receptors, more needs be known about arrangement properties these grafted ligands. This issue is examined here principally atomic force microscopy (AFM) both gold films nanoparticles. Macro-level sessile drop measurements on indicate that, dilute solutions, PEG exhibit similar affinity surface. at nano-level, AFM experiments show differences morphology cohesion adsorbed ligand films. Differences tip/surface adhesion also measured, indicative variations hydrophilicity top surface Analysis force-separation curves suggests a low packing density investigations AuNPs shows that improve dispersion modify behaviour images as-synthesised citric-capped gave nanoparticle diameters. tip tapping Tapping-AFM not suitable detection