Protein‐Enabled Synthesis of Monodisperse Titania Nanoparticles On and Within Polyelectrolyte Matrices

Abstract

Here, the results of a study of the mechanism of bio‐enabled surface‐mediated titania nanoparticle synthesis with assistance of polyelectrolyte surfaces are reported. By applying atomic force microscopy, surface force spectroscopy, circular dichroism, and in situ attenuated total reflection Fourier‐transform infrared spectroscopy, structural changes of rSilC‐silaffin upon its adsorption to polyelectrolyte surfaces prior to and during titania nanoparticle growth are revealed. It is demonstrated that the adhesion of rSilC‐silaffin onto polyelectrolyte surfaces results in its reorganization from a random‐coil conformation in solution into a mixed secondary structure with both random coil and β‐sheet structures presented. Moreover, the protein forms a continuous molecularly thin layer with well‐defined monodisperse nanodomains of lateral dimensions below 20 nm. It is also shown that rSilC embedded inside the polylelectrolyte matrix preserves its titania formation activity. It is suggested that the surface‐mediated, bio‐enabled synthesis of nanostructured materials might be useful to develop general procedures for controlled growth of inorganic nanomaterials on reactive organic surfaces, which opens new perspectives in the design of tailored, in situ grown, hybrid inorganic–organic nanomaterials.

Redox-Active Ultrathin Template of Silk Fibroin: Effect of Secondary Structure on Gold Nanoparticle Reduction

“…In contrast, rSilC being in unordered random-coil conformation in solution cannot provide nanoparticle size uniformity which results in microsized TiO 2 aggregates. 76 We suggest that similar to rSilC the presence of β-sheets in silk II can provide tyrosine ordering in the surface domains seen as silk grainy morphology in Figure 2a. The silk domains facilitate formation of individual, gold nanoparticles, prevent their aggregation, and limit their dimensions to 6 nm, in contrast to large aggregates in silk I.…”

Silk‐on‐Silk Layer‐by‐Layer Microcapsules

“…Both spectra demonstrate a characteristic amide I band (1660-1700 cm − 1 ) which corresponds to the C = O bond in the silk backbone coupled to the N-H bending and C = N stretching modes. [ 46 ] Second, the major peak centered at 1623 cm − 1 is attributed to crystalline β -sheets in both spectra. The deconvolution of the spectra of a silk Preparation of "silk-on-silk" capsules: silk protein random coils are absorbed on silica particles in water solution followed by the formation of a β -sheet-rich structure by treatment with methanol and is then followed by multiple deposition cycles and core removal.…”

Cellulose Nanocrystal Microcapsules as Tunable Cages for Nano- and Microparticles

“…67 Sample was deposited onto silica crystal by drop-cast from aqueous suspension and air dried. The spectra were collected in the range of 4000-900 cm -1 with a resolution 1 cm -1 and accumulation of 100 scans.…”