In SituGeneration of Chiroptically-Active Gold-Peptide Superstructures Promoted by Iodination

Abstract

Peptide-mediated routes to the synthesis of plasmonic nanoparticles have been drawing increasing attention for the development of chiroptically active nanoscale architectures. However, designing a multifunctional peptide able to drive the formation of structurally defined nanomaterials endowed with specific functionalities is still challenging. In this work, iodination has been devised as a strategy to strengthen Au-reduction capability of the amyloidogenic peptide DFNKF and combine it with its distinctive self-assembly features. Thanks to the Au-mediated C—I activation on the phenylalanine iodobenzenes, the peptides yield efficient Au-reduction ability promoting the synthesis of Au nanoparticles, and simultaneously working as templates for their spontaneous self-assembly into spherical superstructures endowed with chiroptical activities. The reaction occurs in situ through a one-pot process in aqueous media. The generality of this approach has been demonstrated using an iodinated derivative of the peptide KLVFF, which also showed reducing and templating abilities forming chiroptically active helical superstructures decorated with Au nanoparticles.

Halogen bonding as a key interaction in the self‐assembly of iodinated diphenylalanine peptides

“…Thus, we consider the reported crystal structures as a reasonable model of the resulting interaction pattern in the presence of highly polarizable halogen atoms. Considering strength and high directionality of halogen bonding, halogenation is not yet fully exploited as a supramolecular tool in the context of peptide‐based nanotechnologies; however, we feel that all the potential showed by halogenation will unlock new and valuable opportunities for the scientific community, as shown in the field of catalysis and in the synthesis of hybrid metal‐peptide nanostructures …”

Chirality at nanoscale for bioscience

“…3E). 36,37 A family of helical gold NP assemblies was prepared with C 18 -(PEP M-ox Au ) 2 (PEP M-ox Au ¼ AYSS-GAPPM ox PPF) by Professor Nathaniel L. Rosi's group. [38][39][40][41] The peptide-conjugated molecules contained an organic tail that directed their self-assembly and bound to gold NPs, which displayed strong plasmonic chiroptical activity, with g-factor values of up to 0.04.…”

Self‐Assembly of Precision Noble Metal Nanoclusters: Hierarchical Structural Complexity, Colloidal Superstructures, and Applications

“…Self‐assembly of plasmonic noble metal NPs has been extensively studied, ranging from noble metal NP supercrystals, [ 195 ] supraparticles, [ 211–214 ] capsids [ 215 ] to protein‐NP superlattices. [ 216 ] Driving forces such as hydrogen bonding, electrostatic interactions, van der Waals interactions, dipolar interactions, CH···π/π···π interactions, amphiphilicity, metal chelation, metal–metal interactions, light‐triggered dipole‐induced attractions, and external templates have been implemented to achieve the self‐assembly in noble metal NPs.…”