Vesicle Formation by the Self-Assembly of Gold Nanoparticles Covered with Fluorinated Oligo(ethylene glycol)-Terminated Ligands and Its Stability in Aqueous Solution

Abstract

Water-stable gold nanoparticle vesicles (GNVs) with hollow interiors have attracted attention due to their great potential for biological applications; however, their preparation through the self-assembly approaches has been restricted due to the limited understanding of their critical mechanistic issues. In this paper, we demonstrate that a fluorinated tetra (ethylene glycol) (FTEG)–terminated tetra (ethylene glycol) (EG4), namely, FTEG–EG4, ligand can self-assemble with gold nanoparticles (5 and 10 nm) into GNVs with a hollow structure in THF due to the solvophobic feature of the ligand. Time-dependent studies showed that the GNVs with a closely packed surface derived from the incomplete and irregular GNVs, but not through the fusion of the GNV precursors. After dialysis in water, the assemblies retained vesicular structures in water, even though GNVs aggregated together, which was initiated by the hydrophobic interactions between the FTEG heads of the surface ligands on GNVs. This study provides a new insight into the design of novel small surface ligands to produce water-stable GNVs for biological applications.

Amphiphilic Polymers for Color Dispersion: Toward Stable and Low-Viscosity Inkjet Ink

“…The self-organizing behaviors of amphiphilic polymers have attracted considerable attention in polymer chemistry, , supramolecular chemistry, − and biochemistry. − Moreover, the application of amphiphilic polymers in the industry has recently become an important subject. For example, amphiphilic polymers have been utilized as dispersants − of nanoparticles. Recent progress in the use of amphiphilic polymers can be found in the effective dispersion of colorants in aqueous media .…”

Size Segregation of Gold Nanoparticles into Bilayer-like Vesicular Assembly

“…These suggested that the motion of the OFB fragment was significantly suppressed and induced solvophobic effects for bundle formation to drive the self-assembly of GNPs . Previous studies demonstrated the solvophobic attraction of fluorinated ligands on the surface of GNPs in THF. − This stronger solvophobicity induced stronger interparticle attraction, which resulted in size segregation. Our previously reported GFL could also self-assemble into size-segregated yolk/shell assembly with the mixtures of Au-5/Au-15 NPs due to enhanced interparticle attraction from the hydrogen bonding provided by the glucose terminal .…”

“…Self-assembly of amphiphilic molecules such as lipids, block copolymers, and proteins provides a powerful approach for the construction of various nano- or microstructures. − Indeed, these nano- or microassemblies have shown great potential for practical applications in materials, , drug delivery, , and other fields. − In order to provide unique physical properties and advanced functionalities to the molecular assemblies, self-assembly of molecularly functionalized metal nanoparticles (MNPs) has been a widely studied topic in the fundamental research in recent years, − due to significantly different physical properties exhibited by the MNPs in comparison to their bulk counterpart. − Currently, most studies are focused on the self-assembly of single-sized MNPs to generate well-ordered nanostructures, further engineering the coupling mode such as plasmon–plasmon, magnetic–magnetic interaction between MNPs to control their collective properties. − …”

Phase Behavior and Aggregate Transition Based on Co-assembly of Negatively Charged Carbon Dots and a pH-Responsive Tertiary Amine Cationic Surfactant

“…With regard to the building blocks, self-assembly usually involves two major types of units. One type includes amphiphilic molecules, polymers, and peptides, and they assemble into lamellar, tubular, vesicular, and micellar structures, with synergic driving forces of electrostatic interaction, hydrogen bonding, hydrophobic interaction, and coordination. − The other kind is some type of nanoarchitectures, such as a nanocrystals, metal–organic frameworks, and inorganic nanoparticles (NPs), including Au, − SiO 2 , Au–Fe 3 O 4 Janus hybrids, and CdTe quantum dots . Because of the flourishing of the synthesis of inorganic nanomaterials as well as a wide range of surface chemistry tuning skills that range from micrometer to nanometer in scale, the past two decades have also seen monumental growth in the self-assembly of nanoparticles, in which interactions among particles and hard-sphere space-filling rules are primary driving forces. ,, Because these two kinds of building blocks differ significantly in their flexibility/rigidity and fluidity/crystallinity, co-assembling them together with a subtle balance remains a fundamental challenge.…”