{"id":{"repo_id":"uwo","oai_identifier":"oai:uwo.scholaris.ca:20.500.14721/38939"},"canonical_url":"https://search.dev.ndltd.org/etd/uwo/oai:uwo.scholaris.ca:20.500.14721/38939","repository":{"repo_id":"uwo","name":"Western University","base_url":"https://uwo.scholaris.ca/server/oai/request"},"display":{"title":"Gold Nanomaterial–Biomolecule Interactions: Influence of Size, Gold Nanomaterial–Biomolecule Interactions: Influence of Size, Surface Chemistry, and Environment Surface Chemistry, and Environment","abstract":"Gold nanomaterials have emerged as great candidates for biomedical applications because of their physicochemical properties and high biocompatibility. However, their performance strongly depends on their interactions with biomolecules and their stability under physiological environments. This dissertation investigates the effect of nanoparticle size, ligand chemistry, proteins, and storage time on the behavior of gold nanoparticles (AuNPs) in biologically relevant settings. Citrate-coated spherical AuNPs ranging from 5 to 60 nm were purchased and studied across three complementary projects. First, time-of-flight secondary ion mass spectrometry (ToF-SIMS) was employed to explain size/ligand- dependent L-cysteine (Cys) adsorption on AuNPs. Cyclic voltammetry was also employed to investigate their electrochemical reactivity. Both techniques revealed enhanced interaction with Cys for smaller nanoparticles driven by increased surface energies. Second, the impact of pH on Cys–AuNP interactions was assessed, showing that mildly acidic conditions can suppress Cys binding, which is greatest between pH 3 and 5 due to the chemical form of Cys. Finally, dynamic light scattering and X-ray absorption spectroscopy were used to characterize the aggregation behavior of the AuNPs of varying sizes and as a function of the presence of bovine serum albumin (BSA). Results indicated that the nanoparticle size strongly affected the extent of aggregation and colloidal stability, with smaller particles having a higher tendency to aggregate, but this effect was reversed in the presence of BSA because of steric repulsion between BSA-coated nanoparticles. Further, circular dichroism and ToF-SIMS indicated that BSA largely retained its secondary structure upon adsorption on the AuNPs. Collectively, these findings advance the mechanistic understanding of how nanomaterials' dimensions, surface chemistry, proteins, and storage time dictate their interactions with proteins and amino acids. The insights gained contribute to the rational design of gold-based nanomaterials with improved stability and biocompatibility, facilitating their potential use in targeted drug delivery, diagnostic imaging, and cancer therapeutics.","abstract_html":"Gold nanomaterials have emerged as great candidates for biomedical applications because of their physicochemical properties and high biocompatibility. However, their performance strongly depends on their interactions with biomolecules and their stability under physiological environments. This dissertation investigates the effect of nanoparticle size, ligand chemistry, proteins, and storage time on the behavior of gold nanoparticles (AuNPs) in biologically relevant settings. Citrate-coated spherical AuNPs ranging from 5 to 60 nm were purchased and studied across three complementary projects. First, time-of-flight secondary ion mass spectrometry (ToF-SIMS) was employed to explain size/ligand- dependent L-cysteine (Cys) adsorption on AuNPs. Cyclic voltammetry was also employed to investigate their electrochemical reactivity. Both techniques revealed enhanced interaction with Cys for smaller nanoparticles driven by increased surface energies. Second, the impact of pH on Cys–AuNP interactions was assessed, showing that mildly acidic conditions can suppress Cys binding, which is greatest between pH 3 and 5 due to the chemical form of Cys. Finally, dynamic light scattering and X-ray absorption spectroscopy were used to characterize the aggregation behavior of the AuNPs of varying sizes and as a function of the presence of bovine serum albumin (BSA). Results indicated that the nanoparticle size strongly affected the extent of aggregation and colloidal stability, with smaller particles having a higher tendency to aggregate, but this effect was reversed in the presence of BSA because of steric repulsion between BSA-coated nanoparticles. Further, circular dichroism and ToF-SIMS indicated that BSA largely retained its secondary structure upon adsorption on the AuNPs. Collectively, these findings advance the mechanistic understanding of how nanomaterials' dimensions, surface chemistry, proteins, and storage time dictate their interactions with proteins and amino acids. The insights gained contribute to the rational design of gold-based nanomaterials with improved stability and biocompatibility, facilitating their potential use in targeted drug delivery, diagnostic imaging, and cancer therapeutics.","abstract_has_math":false,"creators":["Kalantarian, Seyedeh Marzieh"],"institution":"The University of Western Ontario","degree_name":"Ph D","degree_level":null,"degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":[],"advisors":["Hedberg, Yolanda"],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-09-08","date_published":"2025-09-08","updated_at":"2026-07-27T21:56:11Z","subjects":["Protein corona","Cyclic voltammetry","Dynamic light scattering","Time-of-flight secondary ion mass spectrometry","Colloidal stability","Aggregation"],"languages":["en"],"rights":["Attribution-NonCommercial-NoDerivatives 4.0 International"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/20.500.14721/38939","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Hedberg, Yolanda"]},{"key":"dc:creator","label":"Author","values":["Kalantarian, Seyedeh Marzieh"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2025-10-24T15:23:30Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2025-10-24T15:23:30Z"]},{"key":"dc:date.issued","label":"Date","values":["2025-09-08"]},{"key":"dc:publisher","label":"Institution","values":["The University of Western Ontario"]},{"key":"dc:type","label":"Dc Type","values":["thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemistry"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph D"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["The University of Western Ontario"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Protein corona","Cyclic voltammetry","Dynamic light scattering","Time-of-flight secondary ion mass spectrometry","Colloidal stability","Aggregation"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Attribution-NonCommercial-NoDerivatives 4.0 International"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/20.500.14721/38939"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Gold nanomaterials have emerged as great candidates for biomedical applications because of their physicochemical properties and high biocompatibility. However, their performance strongly depends on their interactions with biomolecules and their stability under physiological environments. This dissertation investigates the effect of nanoparticle size, ligand chemistry, proteins, and storage time on the behavior of gold nanoparticles (AuNPs) in biologically relevant settings. Citrate-coated spherical AuNPs ranging from 5 to 60 nm were purchased and studied across three complementary projects. First, time-of-flight secondary ion mass spectrometry (ToF-SIMS) was employed to explain size/ligand- dependent L-cysteine (Cys) adsorption on AuNPs. Cyclic voltammetry was also employed to investigate their electrochemical reactivity. Both techniques revealed enhanced interaction with Cys for smaller nanoparticles driven by increased surface energies. Second, the impact of pH on Cys–AuNP interactions was assessed, showing that mildly acidic conditions can suppress Cys binding, which is greatest between pH 3 and 5 due to the chemical form of Cys. Finally, dynamic light scattering and X-ray absorption spectroscopy were used to characterize the aggregation behavior of the AuNPs of varying sizes and as a function of the presence of bovine serum albumin (BSA). Results indicated that the nanoparticle size strongly affected the extent of aggregation and colloidal stability, with smaller particles having a higher tendency to aggregate, but this effect was reversed in the presence of BSA because of steric repulsion between BSA-coated nanoparticles. Further, circular dichroism and ToF-SIMS indicated that BSA largely retained its secondary structure upon adsorption on the AuNPs. Collectively, these findings advance the mechanistic understanding of how nanomaterials' dimensions, surface chemistry, proteins, and storage time dictate their interactions with proteins and amino acids. The insights gained contribute to the rational design of gold-based nanomaterials with improved stability and biocompatibility, facilitating their potential use in targeted drug delivery, diagnostic imaging, and cancer therapeutics."]},{"key":"dc:title","label":"Title","values":["Gold Nanomaterial–Biomolecule Interactions: Influence of Size, Gold Nanomaterial–Biomolecule Interactions: Influence of Size, Surface Chemistry, and Environment Surface Chemistry, and Environment"]}]}],"canonical_facts":{"dc:contributor.advisor":["Hedberg, Yolanda"],"dc:creator":["Kalantarian, Seyedeh Marzieh"],"dc:date.accessioned":["2025-10-24T15:23:30Z"],"dc:date.available":["2025-10-24T15:23:30Z"],"dc:date.issued":["2025-09-08"],"dc:description.abstract":["Gold nanomaterials have emerged as great candidates for biomedical applications because of their physicochemical properties and high biocompatibility. However, their performance strongly depends on their interactions with biomolecules and their stability under physiological environments. This dissertation investigates the effect of nanoparticle size, ligand chemistry, proteins, and storage time on the behavior of gold nanoparticles (AuNPs) in biologically relevant settings. Citrate-coated spherical AuNPs ranging from 5 to 60 nm were purchased and studied across three complementary projects. First, time-of-flight secondary ion mass spectrometry (ToF-SIMS) was employed to explain size/ligand- dependent L-cysteine (Cys) adsorption on AuNPs. Cyclic voltammetry was also employed to investigate their electrochemical reactivity. Both techniques revealed enhanced interaction with Cys for smaller nanoparticles driven by increased surface energies. Second, the impact of pH on Cys–AuNP interactions was assessed, showing that mildly acidic conditions can suppress Cys binding, which is greatest between pH 3 and 5 due to the chemical form of Cys. Finally, dynamic light scattering and X-ray absorption spectroscopy were used to characterize the aggregation behavior of the AuNPs of varying sizes and as a function of the presence of bovine serum albumin (BSA). Results indicated that the nanoparticle size strongly affected the extent of aggregation and colloidal stability, with smaller particles having a higher tendency to aggregate, but this effect was reversed in the presence of BSA because of steric repulsion between BSA-coated nanoparticles. Further, circular dichroism and ToF-SIMS indicated that BSA largely retained its secondary structure upon adsorption on the AuNPs. Collectively, these findings advance the mechanistic understanding of how nanomaterials' dimensions, surface chemistry, proteins, and storage time dictate their interactions with proteins and amino acids. The insights gained contribute to the rational design of gold-based nanomaterials with improved stability and biocompatibility, facilitating their potential use in targeted drug delivery, diagnostic imaging, and cancer therapeutics."],"dc:identifier.uri":["https://hdl.handle.net/20.500.14721/38939"],"dc:language.iso":["en"],"dc:publisher":["The University of Western Ontario"],"dc:rights":["Attribution-NonCommercial-NoDerivatives 4.0 International"],"dc:subject":["Protein corona","Cyclic voltammetry","Dynamic light scattering","Time-of-flight secondary ion mass spectrometry","Colloidal stability","Aggregation"],"dc:title":["Gold Nanomaterial–Biomolecule Interactions: Influence of Size, Gold Nanomaterial–Biomolecule Interactions: Influence of Size, Surface Chemistry, and Environment Surface Chemistry, and Environment"],"dc:type":["thesis"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_name":["Ph D"],"thesis:institution_name":["The University of Western Ontario"]},"updated_at":"2026-07-27T21:56:11Z"}