Synthesis of Fluorescent Au Clusters Using Self‐Assembled Tripeptides as Reducing Soft Templates

Abstract

In this work, self‐assembling tripeptides as reducing soft templates to synthesize gold nanoclusters (AuNCs) is reported for the first time. Three tripeptides (i. e., CFF, FCC, and PCF) are self‐assembled to form soft templates with different morphologies (nanofibers, nanorings and nanoparticles, respectively) by cryogenic treatment under a mixed solvent condition (tetrahydrofuran/water=8/1). All‐atom molecular dynamics (MD) simulation is used to investigate the self‐assembling process of the tripeptides. Polydispersed AuNCs with different Au core can be obtained in presence of the soft templates and the size of AuNCs shows a dependence on the soft templates. The size of AuNCs are determined by the distribution of the −SH sites on the assembled peptides skeletons and steric hindrance of soft templates. A physical model and an equation are proposed to describe the factors determining the size of aggregate AuNCs on soft templates. Finally, fluorescent AuNCs on FCC soft template were applied to bioimaging.

Peptide Stereochemistry Effects from pKa-Shift to Gold Nanoparticle Templating in a Supramolecular Hydrogel

“…82−84 Interestingly, in those cases, the complexes were stable and could be isolated for structural elucidation, while gold reduction to Au(0) required the introduction of amino acids with gold-chelating, and oxidation-prone, functionalities on the side chain, i.e., Tyr 85 or Cys. 86 We attributed the difference in reactivity to the presence of Asp, whose oxidized dehydroderivative (ΔAsp) can undergo Michael additions more promptly than Phe, 87,88 thus driving the redox reaction toward product formation. Indeed, the oxidized tripeptide byproduct displayed a mass corresponding to ΔPhe-ΔPhe-ΔAsp added with water (ESI section S13).…”

“…Furthermore, the reaction mixture was analyzed by LC–MS, HR–MS, and NMR (Figure A–C and ESI section S13), enabling identification of the unreacted peptide and two other species, one corresponding to the peptide-gold­(III) complex and another one corresponding to the oxidized peptide byproduct. The tetradentate coordination with gold­(III) occurred in a classical mode (see Figure A and ESI section S13, as demonstrated for both peptides 1 and 4 ), via the N-terminal neutral amine, two deprotonated amide nitrogen atoms, and one carboxylate, as already reported for other tripeptides devoid of coordinating groups in their side chains. − Interestingly, in those cases, the complexes were stable and could be isolated for structural elucidation, while gold reduction to Au(0) required the introduction of amino acids with gold-chelating, and oxidation-prone, functionalities on the side chain, i.e., Tyr or Cys . We attributed the difference in reactivity to the presence of Asp, whose oxidized dehydroderivative (ΔAsp) can undergo Michael additions more promptly than Phe, , thus driving the redox reaction toward product formation.…”

Amyloid-like nanofibrous network confined and aligned ultrafine bimetallic nanozymes for smart antibacterial therapy

“…1 a) shows the typical fibril-like structure of LNF/Au 3 Cu 1 HSNW, along with a number of ultrasmall NPs densely and orderly allied on the surfaces of LNFs, which can be ascribed to the excellent space confinement of 1D fibrous structure with an average diameter of 11.2 nm ( Fig. S1 ), and the inherently strong metal ion chelation, particularly the formation of Au–S bonds [ 33 ]. Consequently, ultrafine monometallic Au or bimetallic Au m Cu n NPs with narrow size distribution can regularly grow and scatter on the LNF surfaces ( Fig.…”

Controllable synthesis and electrocatalytic applications of atomically precise gold nanoclusters

“…Lv et al first reported self-assembling tripeptides as reducing soft templates to synthesise atomically precise Au NCs, and the resulting fluorescent Au NCs on the soft template were applied to bio-imaging. 86 Three tripeptides are self-assembled to form soft templates with different morphologies using cryogenic treatment. The size of Au NCs is determined by the distribution of the –SH sites on the template.…”