Decoupling and elucidation of surface-driven processes during inorganic mineralization on virus templates

Abstract

There is a lack of fundamental information about the molecular processes governing biomineralization of inorganic materials to produce nanostructures on biological templates. This information is essential for the directed synthesis of high quality nanomaterials via biotemplating. We characterized palladium (Pd) mineralization via the individual adsorption, reduction, and nanocrystal growth processes, which simultaneously occur during the hydrothermal synthesis on the Tobacco mosaic virus (TMV). The adsorption of precursor and reduction of palladium were decoupled through UV-vis Spectroscopy and in situ X-ray absorption spectroscopy studies. The role of additional cysteine (Cys) residues, ionic strength, and coating density on the fundamental parameters describing these processes were quantitatively evaluated. Primary nanocrystal growth and structural orientation of Pd nanoparticles was characterized using in situ small angle X-ray scattering. The adsorption, reduction of Pd species, and nanocrystal sizes were significantly changed on addition of Cys residues to the amino terminus of the TMV coat protein. Reduction of Pd on an already coated virion was dependent on the Pd surface area, and was hindered by the presence of residual salt. Furthermore, trends in Pd adsorption intensity and capacity suggested that chloride ions affected the adsorption equilibrium. Application of this fundamental approach with further optimization of parameters dictating biomineralization would facilitate directed synthesis and scale up of bioinorganic systems.

Engineering Tobacco Mosaic Virus and Its Virus‐Like‐Particles for Synthesis of Biotemplated Nanomaterials

“…However, the adsorption process is frequently described by a single‐step Langmuir isotherm that is solely driven by covalent interactions, for example, palladium on TMV. [ 41 ] As metal ion precursor adsorption and reduction are the fundamental processes that drive metal coating formation, the oxidation potential of surface accessible residues must be sufficient to drive metal reduction ( Table 2 ). Amino acid residues that are easily oxidized, such as, cysteine, tyrosine, and lysine, more readily interact with metals driving deposition.…”

“…The metal precursor ions adsorb and are chemically reduced on the viral particle surfaces at many adsorption and nucleation sites to form a metallic nanomaterial. [41,42] The chemical interactions that drive metal precursor adsorption and reduction to a metal deposit are not well understood. However, the adsorption process is frequently described by a single-step Langmuir isotherm that is solely driven by covalent interactions, for example, palladium on TMV.…”

Engineering Tobacco Mosaic Virus, Barley Stripe Mosaic Virus, and their Virus-Like-Particles for Synthesis of Biotemplated Nanomaterials

“…Metal nanoparticles are frequently synthesized spontaneously on viral biotemplates using aqueous metal solutions. The metal precursor ions adsorb and are chemically reduced on the viral particle surfaces at many adsorption and nucleation sites to form a metallic nanomaterial [38,39]. The chemical interactions that drive metal precursor adsorption and reduction are not well understood.…”

“…However, the adsorption process is frequently described by a single-step Langmuir isotherm that is solely driven by covalent interactions, e.g. palladium on TMV [38]. As metal ion precursor adsorption and reduction are the fundamental processes that drives metal coating formation, the oxidation potential of surface accessible residues must be sufficient to drive metal reduction (Table 2).…”

Bio-Templating: An Emerging Synthetic Technique for Catalysts. A Review

“…Also, viral envelopes, bacterial cell surface layer proteins, microalgae, both eukaryotic and procaryotic cells, and biofilms are of great interest [12][13][14][15]. In particular, rod-like viruses such as the tobacco mosaic virus provide an attractive approach because their hollow structures offer a viable template to guide the synthesis of nanoparticles and control their sizes and constitution [16]. Another virus that has been used as a pattern for biotemplating approaches is the M13 phage, as its genetically engineered mutants present modifications on the surface that bind to nanoparticles or nanotubes, improving the functionality of the material [17].…”