Modulating the Physicochemical and Structural Properties of Gold-Functionalized Protein Nanotubes through Thiol Surface Modification

Abstract

Biomolecules are advantageous scaffolds for the synthesis and ordering of metallic nanoparticles. Rotavirus VP6 nanotubes possess intrinsic affinity to metal ions, a property that has been exploited to synthesize gold nanoparticles over them. The resulting nanobiomaterials have unique properties useful for novel applications. However, the formed nanobiomaterials lack of colloidal stability and flocculate, limiting their functionality. Here we demonstrate that it is possible to synthesize thiol-protected gold nanoparticles over VP6 nanotubes, which resulted in soluble nanobiomaterials. With this strategy, it was possible to modulate the size, colloidal stability, and surface plasmon resonance of the synthesized nanoparticles by controlling the content of the thiolated ligands. Two types of water-soluble ligands were tested, a small linear ligand, sodium 3-mercapto-1-propanesulfonate (MPS), and a bulky ligand, 5-mercaptopentyl β-D-glucopyranoside (GlcC5SH). The synthesized nanobiomaterials had a higher stability in suspension, as determined by Z-potential measurements. To the extent of our knowledge, this is the first time that a rational strategy is developed to modulate the particular properties of metal nanoparticles in situ synthesized over a protein bioscaffold through thiol coating, achieving a high spatial and structural organization of nanoparticles in a single integrative hybrid structure.

Analytical Characterization of Size-Dependent Properties of Larger Aqueous Gold Nanoclusters

“…The Debye–Hückel parameter from μ is applicable when the particle radius is sufficiently large; in the case of ultrasmall particles like Au 144 and Au 102 , it has no significant effect on μ, explaining the relative consistency of the values obtained at different ionic strength (0–100 mM NaOH). In contrast, for Au nanoparticles in the range of 15–200 nm, the ζ and μ values are highly influenced by particle size and electrolyte concentration. − Finally, EC measurements showed a clear linear dependency on the ionic strength of the solution, with no significant differences among all three AuNCs. Gold nanoclusters dissolved in water without any added salts showed a conductivity of 0.263–0.405 mS cm –1 .…”

Tobacco Mosaic Virus with Peroxidase-Like Activity for Cancer Cell Detection through Colorimetric Assay

“…However, the TMV coated metal nanoparticles were unavoidable to aggregate due to the high interface energy of metal nanoparticles . Sodium 3-mercapto-1-propanesulfonate (MPS) has been previously used to stabilize metal nanoparticles because of their sulfonate groups with negative charge and sulfhydryl, which has strong chelate affinity to metal nanoparticles. , In this work, MPS was used to protect TMV-Pt NPs through generating strong electrostatic repulsion between Pt NPs. Consequently, TMV-Pt NPs were able to disperse in water and remained the good monodispersity as TMV (Figure A).…”

Design of Bioelectrochemical Interfaces Assisted by Molecular Dynamics Simulations

“…Therefore, our previous data on viral capsids can serve as a workflow to identify candidate proteins or enzymes for construction of BEI devices. Altogether, theoretical and experimental reports on BEI [41][42][43] are examples of how structural information could help to elucidate the behavior of biological systems during electrochemical reactions. Nonetheless, the aforementioned studies depend on structural information from biomolecules, and certain biomolecules are very complex and highly labile, which difficult elucidation of atomic positions.…”