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dc.contributor.advisor Mosuang, T.E.
dc.contributor.author Makgoba, Malesela Walter
dc.contributor.other Sikhwivhilu, L. M.
dc.contributor.other Mhlanga, N.
dc.date.accessioned 2025-10-08T10:49:54Z
dc.date.available 2025-10-08T10:49:54Z
dc.date.issued 2024
dc.identifier.uri http://hdl.handle.net/10386/5097
dc.description Thesis (Ph. D. (Physics)) -- University of Limpopo, 2024 en_US
dc.description.abstract Interface interactions of Au- and Ag-nanoparticles with fibrin protein molecules have been investigated using both computational and experimental approaches. Computational approach used Monte Carlo, density functional theory, and classical molecular dynamics simulations. Sampling of Au(19)/Ag(19), Au(38)/Ag(38), Au(55)/Ag(55), and Au(79)/Ag(79) nanospheres against different possible combinations of 1, 2, 3, and 4-fibrin protein chains were explored for possible Au/Ag-nanosphere+fibrin corona formations. Negative adsorption energies were recorded for some possible Au(19)/Ag(19)+1, 2, 3, and 4-fibrin; Au(38)/Ag(38)+1, 2, 3, and 4-fibrin; Au(55)/Ag(55)+1, 2, 3, and 4-firbin; and Au(79)/Ag(79)+1, 2, 3, and 4-fibrin corona complexes. Au(55)+1, 2, 3, and 4-fibrin corona complexes recorded the most energetically stable adsorption energies of -2.99, -2.73 and -3.00 eV. Similarly, Ag(55)+1, 2, 3, and 4-fibrin corona complexes also recorded the most energetically stable adsorption energies of -2.99, -2.72 and -3.27 eV. Radial distribution functions approximations showed Au-H having the shortest bond lengths of 2.37, 2.47, 2.57, and 2.37 Å respectively relative to Au(19), Au(38), Au(55), and Au(79) nanospheres. Likewise, Ag-H registered the shortest bond lengths of 2.11, 2.45, 2.57, 2.47 Å respectively relative to Ag(19), Ag(38), Ag(55), and Ag(79) nanospheres. Mean square displacements and diffusion coefficients constant hint on H, C, N, and O functional group atoms having good diffusion probabilities onto Au- and Ag-nanospheres. H, C, and N functional group atoms recorded the highest diffusion coefficient constants onto the Au(55) nanosphere whilst H, C, N, and O functional group atoms further recorded the highest diffusion coefficient constants onto the Ag(79) nanosphere. Mülliken charges analysis lead to either enhanced negative or positive charges onto specified carbon (C1, C2, and C3) atoms after Au-nanosphere+fibrin or Ag-nanosphere+firbin corona formations. Radius of gyration further suggest a tighter packing on the adsorption of fibrin molecules onto Au(38)/Ag(38), Au(55)/Ag(55), and Au(79)/Ag(79) nanospheres in the following preference: Au(79)/Ag(79) > Au(55)/Ag(55) > Au(38)/Ag(38). Experimentally, Au- and Ag-nanoparticles were synthesised using sodium citrate induced method, thereafter, conjugated with fibrin proteins for adsorption studies. Average spherical diameter sizes 11, 18, 45 and 50 nm of Au-nanoparticles and 12, 14, and 26 nm of Ag-nanoparticles were considered for the conjugation process. Possible adsorption and formation of Au/Ag-nanoparticle+fibrin protein corona complexes were verified using UV-vis and FTIR spectroscopies, Zeta potential, and TEM imaging. UV-vis blue shift was observed on fibrin conjugated Au-nanoparticles relative to the unconjugated Au-nanoparticles, confirming the formation of Au/Ag-nanoparticle+fibrin protein corona complexes. FTIR spectra provided a trace of possible fibrin functional group atoms bonding with Au- and Ag-nanoparticles surface atoms in the possible formation of Au/Ag-nanoparticle+fibrin protein corona complexes. TEM imaging was also utilised to observe and estimate nanoparticles distribution and sizes chronologically. Unconjugated Au-nanoparticles materialise as agglomerates of nano-clusters whilst fibrin conjugated Au-nanoparticles appear as dispersed individual random nanoparticles. On the other hand, unconjugated Ag-nanoparticles occur as scattered irregular individual nanoparticles which agglomerate into nano-clusters upon conjugation with fibrin protein molecules. en_US
dc.format.extent xvi, 212 leaves en_US
dc.language.iso en en_US
dc.relation.requires PDF en_US
dc.subject Interface en_US
dc.subject Interactions en_US
dc.subject Biological molecules en_US
dc.subject Precious metal nanoparticles en_US
dc.subject.lcsh Metal nanoparticles en_US
dc.subject.lcsh Biomolecules en_US
dc.subject.lcsh Interface circuits en_US
dc.title Understanding the interface interactions between biological molecules and precious metal nanoparticles en_US
dc.type Thesis en_US


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