219641-34-6Relevant articles and documents
Probing resistance to protein adsorption of oligo(ethylene glycol)-terminated self-assembled monolayers by scanning force microscopy
Feldman,Haehner,Spencer,Harder,Grunze
, p. 10134 - 10141 (1999)
Functionalized scanning force microscope (SFM) probes were used to investigate and to mimic the interaction between fibrinogen and self-assembled monolayers (SAMs) of methoxytri(ethylene glycol) undecanethiolates -S(CH2)11(OCH2CH2) 3OCH3 (EG3-OMe) on gold and silver surfaces. The SAMs on gold are resistant to protein adsorption, whereas the films on silver adsorb variable amounts of fibrinogen. Experiments were performed with both charged and hydrophobic tips as models for local protein structures to determine the influence of these parameters on the interaction with the SAMs. A striking difference between the two monolayers was established when the forces were measured in an aqueous environment with hydrophobic probes. While a long-range attractive hydrophobic interaction was observed for the EG3-OMe on silver, a repulsive force was measured for EG3-OMe on gold. The strong dependence of the repulsive force for the EG3-OMe-gold system upon the solution ionic strength suggests that this interaction has a significant electrostatic contribution. The observed differences are attributed to the distinct molecular conformations of the oligo-(ethylene glycol) tails on the gold-supported (helical) and silver-supported ("all-trans") monolayers. A comparison of the force/distance curves for the EG3-OMe SAMs with those measured under identical conditions on end-grafted poly(ethylene glycol) (PEG 2000) on gold further emphasizes that the nature of the repulsive forces originating from the short-chain oligomers is unique and not related to a "steric repulsion" effect.
Nanoparticle-Based Receptors Mimic Protein-Ligand Recognition
Riccardi, Laura,Gabrielli, Luca,Sun, Xiaohuan,De Biasi, Federico,Rastrelli, Federico,Mancin, Fabrizio,De Vivo, Marco
, p. 92 - 109 (2017)
The self-assembly of a monolayer of ligands on the surface of noble-metal nanoparticles dictates the fundamental nanoparticle's behavior and its functionality. In this combined computational-experimental study, we analyze the structure, organization, and dynamics of functionalized coating thiols in monolayer-protected gold nanoparticles (AuNPs). We explain how functionalized coating thiols self-organize through a delicate and somehow counterintuitive balance of interactions within the monolayer itself and with the solvent. We further describe how the nature and plasticity of these interactions modulate nanoparticle-based chemosensing. Importantly, we found that self-organization of coating thiols can induce the formation of binding pockets in AuNPs. These transient cavities can accommodate small molecules, mimicking protein-ligand recognition, which could explain the selectivity and sensitivity observed for different organic analytes in NMR chemosensing experiments. Thus, our findings advocate for the rational design of tailored coating groups to form specific recognition binding sites on monolayer-protected AuNPs.
Evidence for why tri(ethylene oxide) functionalized Si-C linked monolayers on Si(111) have inferior protein antifouling properties relative to the equivalent alkanethiol monolayers assembled on gold
Boecking, Till,Gal, Michael,Gaus, Katharina,Gooding, J. Justin
, p. 660 - 663 (2005)
High quality methoxy-terminated monolayers containing a tri(ethylene oxide) moiety were formed on Si(111)-H surfaces in thermal hydrosilylation reactions. X-ray photoelectron spectroscopy, contact angle, and X-ray reflectivity measurements suggested that the suboptimal protein anti-fouling properties of these Si-C linked monolayers were due to a reduced lateral packing density of the chains resulting in a disordered layer with insufficient internal and external hydrophilicity. CSIRO 2005.
