In Situ Generation of Chiroptically-Active Gold-Peptide Superstructures Promoted by Iodination.

Claudia Pigliacelli,Alessandro Gori,Kavitha Buntara Sanjeeva,Andrea Pizzi,Nonappa Nonappa,Pierangelo Metrangolo,Francesca Baldelli Bombelli

doi:10.1021/acsnano.8b08805

Claudia Pigliacelli, Alessandro Gori + Show 5 more

Open Access

https://doi.org/10.1021/acsnano.8b08805

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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.

Highlights

I nspired by biomineralization processes,[1,2] peptide-mediated synthesis of gold nanoparticles (GNPs) exploits peptides’ ability to act as reducing and capping agents,[3,4] allowing in situ GNP nucleation and growth in mild synthetic conditions.[5,6] peptides are endowed with peculiar self-assembly properties, widely employed to fabricate nanostructures.[7]
The generality of this approach has been demonstrated using an iodinated derivative of the peptide KLVFF, which showed reducing and templating abilities forming chiroptically active helical superstructures decorated with Au nanoparticles
The approach developed in this study offers direct access to chiroptically active Au−peptide superstructures through an environmentally benign procedure

Summary

Introduction

I nspired by biomineralization processes,[1,2] peptide-mediated synthesis of gold nanoparticles (GNPs) exploits peptides’ ability to act as reducing and capping agents,[3,4] allowing in situ GNP nucleation and growth in mild synthetic conditions.[5,6] peptides are endowed with peculiar self-assembly properties, widely employed to fabricate nanostructures.[7]. 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 generality of this approach has been demonstrated using an iodinated derivative of the peptide KLVFF, which showed reducing and templating abilities forming chiroptically active helical superstructures decorated with Au nanoparticles.

Results

Conclusion