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...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.展开更多
基金supported by the National Science Foundation(NSF)under Grant CBET-2335597The Shiley Foundation,NIH(S10 OD023555)+2 种基金UC San Diego Materials Research Science and Engineering Center(UCSD MRSEC,Grant#DMR-2011924)University of California,San Diego Cellular and Molecular Medicine Electron Microscopy Core(UCSD-CMM-EM Core,RRID:SCR_022039)for equipment access and technical assistance(partly supported by NIH award S10 OD023527)U.S.National Science Foundation Grants OAC-2138259,OAC-2138286,OAC-2138307,OAC-2137603,and OAC-2138296.
文摘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.
