Mechanism of Cationic Peptide‐Induced Assembly of Gold Nanoparticles: Modulation of Electrostatic Repulsion
ABSTRACT The aggregation of plasmonic nanoparticles can lead to new and controllable properties useful for numerous applications. We recently showed the reversible aggregation of gold nanoparticles (AuNPs) via a small, cationic di‐arginine peptide; however, the mechanism underlying this aggregation...
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Wiley
2025-06-01
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| Online Access: | https://doi.org/10.1002/agt2.70043 |
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| author | Benjamin Lam Robert Ramji Margaret Mullooly Kristina D. Closser Tod A. Pascal Jesse V. Jokerst |
| author_facet | Benjamin Lam Robert Ramji Margaret Mullooly Kristina D. Closser Tod A. Pascal Jesse V. Jokerst |
| author_sort | Benjamin Lam |
| collection | DOAJ |
| description | ABSTRACT The aggregation of plasmonic nanoparticles can lead to new and controllable properties useful for numerous applications. We recently showed the reversible aggregation of gold nanoparticles (AuNPs) via a small, cationic di‐arginine peptide; however, the mechanism underlying this aggregation is not yet comprehensively understood. Here, we seek insights into the intermolecular interactions of cationic peptide‐induced assembly of citrate‐capped AuNPs by empirically measuring how peptide identity impacts AuNP aggregation. We examined the nanoscale interactions between the peptides and the AuNPs via UV‐vis spectroscopy to determine the structure‐function relationship of peptide length and charge on AuNP aggregation. Careful tuning of the sequence of the di‐arginine peptide demonstrated that the mechanism of assembly is driven by a reduction in electrostatic repulsion. We show that acetylated N‐terminals and carboxylic acid C‐terminals decrease the effectiveness of the peptide in inducing AuNP aggregation. The increase in peptide size through the addition of glycine or proline units hinders aggregation and leads to less redshift. Arginine‐based peptides were also found to be more effective in assembling the AuNPs than cysteine‐based peptides of equivalent length. We also illustrate that aggregation is independent of peptide stereochemistry. Finally, we demonstrate the modulation of peptide‐AuNP behavior through changes to the pH, salt concentration, and temperature. Notably, histidine‐based and tyrosine‐based peptides could reversibly aggregate the AuNPs in response to the pH. |
| format | Article |
| id | doaj-art-665eb8f1b652421fb34c674f77c239e8 |
| institution | OA Journals |
| issn | 2692-4560 |
| language | English |
| publishDate | 2025-06-01 |
| publisher | Wiley |
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| spelling | doaj-art-665eb8f1b652421fb34c674f77c239e82025-08-20T02:37:36ZengWileyAggregate2692-45602025-06-0166n/an/a10.1002/agt2.70043Mechanism of Cationic Peptide‐Induced Assembly of Gold Nanoparticles: Modulation of Electrostatic RepulsionBenjamin Lam0Robert Ramji1Margaret Mullooly2Kristina D. Closser3Tod A. Pascal4Jesse V. Jokerst5Aiiso Yufeng Li Family Department of Chemical and Nano Engineering University of California, San Diego La Jolla California USAAiiso Yufeng Li Family Department of Chemical and Nano Engineering University of California, San Diego La Jolla California USADepartment of Chemistry and Biochemistry California State University, Fresno Fresno California USADepartment of Chemistry and Biochemistry California State University, Fresno Fresno California USAAiiso Yufeng Li Family Department of Chemical and Nano Engineering University of California, San Diego La Jolla California USAAiiso Yufeng Li Family Department of Chemical and Nano Engineering University of California, San Diego La Jolla California USAABSTRACT The aggregation of plasmonic nanoparticles can lead to new and controllable properties useful for numerous applications. We recently showed the reversible aggregation of gold nanoparticles (AuNPs) via a small, cationic di‐arginine peptide; however, the mechanism underlying this aggregation is not yet comprehensively understood. Here, we seek insights into the intermolecular interactions of cationic peptide‐induced assembly of citrate‐capped AuNPs by empirically measuring how peptide identity impacts AuNP aggregation. We examined the nanoscale interactions between the peptides and the AuNPs via UV‐vis spectroscopy to determine the structure‐function relationship of peptide length and charge on AuNP aggregation. Careful tuning of the sequence of the di‐arginine peptide demonstrated that the mechanism of assembly is driven by a reduction in electrostatic repulsion. We show that acetylated N‐terminals and carboxylic acid C‐terminals decrease the effectiveness of the peptide in inducing AuNP aggregation. The increase in peptide size through the addition of glycine or proline units hinders aggregation and leads to less redshift. Arginine‐based peptides were also found to be more effective in assembling the AuNPs than cysteine‐based peptides of equivalent length. We also illustrate that aggregation is independent of peptide stereochemistry. Finally, we demonstrate the modulation of peptide‐AuNP behavior through changes to the pH, salt concentration, and temperature. Notably, histidine‐based and tyrosine‐based peptides could reversibly aggregate the AuNPs in response to the pH.https://doi.org/10.1002/agt2.70043DLVO theorygold nanoparticlesintermolecular interactionspeptidesreversible aggregation |
| spellingShingle | Benjamin Lam Robert Ramji Margaret Mullooly Kristina D. Closser Tod A. Pascal Jesse V. Jokerst Mechanism of Cationic Peptide‐Induced Assembly of Gold Nanoparticles: Modulation of Electrostatic Repulsion Aggregate DLVO theory gold nanoparticles intermolecular interactions peptides reversible aggregation |
| title | Mechanism of Cationic Peptide‐Induced Assembly of Gold Nanoparticles: Modulation of Electrostatic Repulsion |
| title_full | Mechanism of Cationic Peptide‐Induced Assembly of Gold Nanoparticles: Modulation of Electrostatic Repulsion |
| title_fullStr | Mechanism of Cationic Peptide‐Induced Assembly of Gold Nanoparticles: Modulation of Electrostatic Repulsion |
| title_full_unstemmed | Mechanism of Cationic Peptide‐Induced Assembly of Gold Nanoparticles: Modulation of Electrostatic Repulsion |
| title_short | Mechanism of Cationic Peptide‐Induced Assembly of Gold Nanoparticles: Modulation of Electrostatic Repulsion |
| title_sort | mechanism of cationic peptide induced assembly of gold nanoparticles modulation of electrostatic repulsion |
| topic | DLVO theory gold nanoparticles intermolecular interactions peptides reversible aggregation |
| url | https://doi.org/10.1002/agt2.70043 |
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