Formation of Plasmonic Vesicles Through the Self-Assembly of Sugar-Terminated Fluorinated Oligo(ethylene glycol) Ligand-Tethered Gold Nanoparticles

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

“…On the other hand, no fusion of GNV precursors was observed in the slow self-organization process of FTEG-EG4 and Au-10 NPs in this study. This formation mechanism might be different from our previously reported formation mechanism via the fusion of precursors, driven by the stronger attraction between the surface ligands of GNPs. − …”

“…Even though some dispersed GNVs can be observed, most were aggregated. The FTEG-EG4 is different from those ligands used in our previous works. − Low solubility of GNPs with FTEG-EG4 in aqueous solution may lead to stabilize the formed GNVs in aqueous solution, but the hydrophobic attraction of the FTEG head between the surfaces of GNVs promoted the aggregation process of GNVs during dialysis.…”

“…However, it formed aggregations with Au-15 or Au-20 NPs (Figures b and S8). Based on our previous studies, the balance between attractive and repulsive forces is important for GNV formation of the small molecule-modified GNPs. − Larger GNPs generated the shrunken assemblies or aggregations due to the stronger attractive interaction as van der Waals force between larger GNPs, while the ligands attached to the surface of GNPs may affect the repulsive forces. Kegel and co-workers used Monte Carlo simulations to show that a shell composed of NPs can be stabilized by short-range attraction and long-range repulsion .…”

“…In the case of the self-assembly for GNV formation based on small molecules, the balance between interparticle attraction and repulsion, which are principally contributed by the ligands on the surface of GNPs, is important. − Compared with multicomplex polymers, the self-assembly using the small surface ligands with low molecular weights and controllable interactions to cover GNPs for GNV formation are suitable for their mechanistic studies and are desirable for their plasmonic characteristics. − Therefore, the design of small organic ligands with unique surface features and controllable inter- or intramolecular interactions for GNV formation is an important fundamental research direction. Most previously reported small surface ligands for GNV formation are based on a solvophilic head linked with a solvophobic part. − A balance between the solvophilic and solvophobic parts of a ligand is important for GNV formation. Recently, we developed a nontemplated self-assembly approach to fabricate GNVs using a semifluorinated oligo­(ethylene glycol) ligand (SFL), a small organic molecule, tethered GNPs with sizes of 5, 10, and 20 nm based on the solvophobic effects .…”

“…To increase the stability of GNVs, we designed a glucose-terminated fluorinated oligo­(ethylene glycol) ligand (GFL). Because the glucose head can form inter- and intramolecular hydrogen bonds, they could provide strong attraction than the OEG head of the SFL did. , To further prove that the competing interactions including attraction and repulsion contributed to GNV formation, a carboxylic acid-terminated fluorinated oligo­(ethylene glycol) ligand (CFL) was designed to self-assemble with 30 nm GNPs into vesicles . In the case of GFL- or CFL-related ligands, we focused on the direction of increasing attraction or introducing a charge on the surface ligands compared with that of SFLs; however, the GNVs in our previous report could be dispersed in an organic solvent but collapsed after transfer into water .…”