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You searched for subject:(Proteinogenic Biomolecules). One record found.

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1. Rahnemaye Rahsepar, Seyedeh Fatemeh. Surface Interactions of Proteinogenic Biomolecules and Gold Nanostructures on Si(111)7×7.

Degree: 2015, University of Waterloo

The site-specific surface interactions and film growth mechanisms of adsorption of gold and of proteinogenic sulfur-containing amino acids, i.e., L-cysteine and L-methionine, on Si(111)7×7 are studied for the first time by X-ray photoelectron spectroscopy (XPS) and Scanning Tunneling Microscopy (STM) at room temperature under ultrahigh vacuum condition. The results are supported with large-scale density functional theory (DFT) calculations with dispersion correction for biomolecule adsorbates, to provide precise modeling of the equilibrium adsorption geometries of adsorbates on a Si200H49 slab used as the model Si(111)7×7 surface. Growth evolution of gold on the 7×7 surface is found to follow the Stranski-Krastanov mode, starting with completion of two distinct gold silicide layers to individual gold nanoisland formation. Of special interest is the formation of two-dimensional self-assembled gold silicide honeycomb nanonetwork at 0.76 monolayer coverage at room temperature. Observed for the first time, this honeycomb nanonetwork is made up of six triangular gold clusters (surrounding each corner hole) interconnected to one another at the dimer rows of the Si(111)7×7 substrate. With the corner holes of the 7×7 surface exposed, this novel gold silicide template offers a unique honeycomb network (4 nm in grids size) for surface functionalization and a nanopore pattern (~1 nm in pore size) for molecular trapping application. In analogy to common simple aliphatic amino acids, such as glycine and alanine, sulfur-containing aliphatic amino acids, cysteine and methionine, exhibit an “universal” three-stage growth sequence on Si(111)7×7 surface at room temperature under ultra-high vacuum condition. In particular, the biomolecule first anchors to specific dangling bond sites on the 7×7 reconstruction via strong short-range covalent bonds (through Si–N and/or Si–S linkages in unidentate and/or bidentate arrangement of cysteine adsorption, and through Si–N linkage in unidentate arrangement of methionine adsorption), forming the interfacial layer (the first adlayer). This is then followed by the formation of a transitional layer (the second adlayer) and finally of a zwitterionic film (multilayer), both of which are driven by intralayer and interlayer hydrogen bonding. XPS study of thermal stabilities of these adlayers indicates that these proteinogenic biomolecules can be used to transform a highly reactive Si(111)7×7 surface to not just a permanent bio-organic surface but also a semi-permanent (or renewable) and a temporary bio-organic surfaces by manipulating the exposure and the post-annealing temperature. Our results on all the adsorbed proteinogenic biomolecules on Si(111)7×7 surface studied to date enable us to construct a reference XPS data table to guide future studies of biofilm growth on reconstructed Si(111) surface. The STM study of adsorbed cysteine on Si(111)7×7 provides strong evidence for coverage-dependent adsorption structures of cysteine, from bidentate to unidentate attachments to self-assembled…

Subjects/Keywords: Surface Interactions; Proteinogenic Biomolecules; Gold Nanostructures; Si(111)7×7 Surface

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APA (6th Edition):

Rahnemaye Rahsepar, S. F. (2015). Surface Interactions of Proteinogenic Biomolecules and Gold Nanostructures on Si(111)7×7. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/9671

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Rahnemaye Rahsepar, Seyedeh Fatemeh. “Surface Interactions of Proteinogenic Biomolecules and Gold Nanostructures on Si(111)7×7.” 2015. Thesis, University of Waterloo. Accessed October 16, 2019. http://hdl.handle.net/10012/9671.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Rahnemaye Rahsepar, Seyedeh Fatemeh. “Surface Interactions of Proteinogenic Biomolecules and Gold Nanostructures on Si(111)7×7.” 2015. Web. 16 Oct 2019.

Vancouver:

Rahnemaye Rahsepar SF. Surface Interactions of Proteinogenic Biomolecules and Gold Nanostructures on Si(111)7×7. [Internet] [Thesis]. University of Waterloo; 2015. [cited 2019 Oct 16]. Available from: http://hdl.handle.net/10012/9671.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Rahnemaye Rahsepar SF. Surface Interactions of Proteinogenic Biomolecules and Gold Nanostructures on Si(111)7×7. [Thesis]. University of Waterloo; 2015. Available from: http://hdl.handle.net/10012/9671

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

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