Journal
APPLIED SURFACE SCIENCE
Volume 574, Issue -, Pages -Publisher
ELSEVIER
DOI: 10.1016/j.apsusc.2021.151386
Keywords
Atomic force microscopy; Functionalisation; Drug delivery; Gold nanoparticle; Ligand; Pegylation
Categories
Funding
- Department of the Economy (DeC) Northern Ireland
Ask authors/readers for more resources
Gold nanoparticles functionalized with PEG and peptide ligands were examined using atomic force microscopy (AFM) to study their morphology and properties. The results showed that PEG and peptide ligands have similar affinity to the gold surface, but exhibit differences in morphology, cohesion, and hydrophilicity at the nanolevel.
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 the ligands with blood proteins and specific cell receptors, more needs to be known about the arrangement and properties of these grafted ligands. This issue is examined here principally with atomic force microscopy (AFM) for ligands grafted to both gold films and gold nanoparticles. Macro-level sessile drop measurements on the films indicate that, in dilute solutions, the PEG and peptide ligands exhibit similar affinity to the gold surface. However, at the nanolevel, AFM experiments show differences in the morphology and cohesion of the adsorbed ligand films. Differences in tip/surface adhesion are also measured, indicative of variations of hydrophilicity for the top surface of these ligand films. Analysis of force-separation curves suggests a low packing density of PEG ligands. AFM investigations of functionalized AuNPs shows that the ligands improve dispersion and modify the tip/surface adhesion behaviour on the nanoparticles. However, AFM images of as-synthesised citric-capped and functionalized AuNPs gave similar nanoparticle diameters. Analysis of the AFM tip tapping on the AuNPs suggests that Tapping-AFM is not suitable for detection of low packing density ligands.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available