- Title
- Fractal-like R5 assembly promote the condensation of silicic acid into silica particles
- Creator
- Gascoigne, Levena; Magana, Jose Rodrigo; Atkins, Dylan Luke; Sproncken, Christian C. M.; Gumi-Audenis, Berta; Schoenmakers, Sandra M. C.; Wakeham, Deborah; Wanless, Erica J.; Voets, Ilja Karina
- Relation
- Journal of Colloid and Interface Science Vol. 598, Issue 15 September 2021, p. 206-212
- Publisher Link
- http://dx.doi.org/10.1016/j.jcis.2021.04.030
- Publisher
- Elsevier
- Resource Type
- journal article
- Date
- 2021
- Description
- Hypothesis: Despite advances in understanding the R5 (SSKKSGSYSGKSGSKRRIL) peptide-driven bio-silica process, there remains significant discrepancies regarding the physicochemical characterization and the self-assembling mechanistic driving forces of the supramolecular R5 template. This paper investigates the self-assembly of R5 as a function of monovalent (sodium chloride) and multivalent salt (phosphate) to determine if assembly is phosphate ion concentration dependent. Additionally, we hypothesize that the assembled R5 aggregates do not resemble a micelle or unimer structure as proposed in current literature. Experiments: R5 peptides were synthesized, and aggregates evaluated for their size, morphology, and association state as a function of salt and ionic strength concentration via dynamic and static light scattering, small angle X-ray and neutron scattering and cryogenic transmission electron microscopy. Furthermore, we compare the proposed R5 template to precipitated silica by scanning electron microscopy. Findings: R5 peptides assemble into large aggregates due to multivalence bridging and the decrease in electrostatic repulsion due to ionic strength. We elucidate the structure of R5 aggregates as mass-fractals composed of small spherical aggregates. Moreover, we discover that phosphate ions not only have a significant role in driving the growth of the R5 scaffold, but additionally in driving the polycondensation of silicic acid during the bio-silification process via electrostatic interactions.
- Subject
- supramolecular chemistry; peptides; template synthesis; self-assembly; silica; silaffin; biomineralization
- Identifier
- http://hdl.handle.net/1959.13/1433252
- Identifier
- uon:39194
- Identifier
- ISSN:0021-9797
- Language
- eng
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