Fabrication of Supramolecular n/p-Nanowires via Coassembly of Oppositely Charged Peptide-Chromophore Systems in Aqueous Media

Abstract

Fabrication of supramolecular electroactive materials at the nanoscale with well-defined size, shape, composition, and organization in aqueous medium is a current challenge. Herein we report construction of supramolecular charge-transfer complex one-dimensional (1D) nanowires consisting of highly ordered mixed-stack π-electron donor-acceptor (D-A) domains. We synthesized n-type and p-type β-sheet forming short peptide-chromophore conjugates, which assemble separately into well-ordered nanofibers in aqueous media. These complementary p-type and n-type nanofibers coassemble via hydrogen bonding, charge-transfer complex, and electrostatic interactions to generate highly uniform supramolecular n/p-coassembled 1D nanowires. This molecular design ensures highly ordered arrangement of D-A stacks within n/p-coassembled supramolecular nanowires. The supramolecular n/p-coassembled nanowires were found to be formed by A-D-A unit cells having an association constant (K) of 5.18 × 10 M. In addition, electrical measurements revealed that supramolecular n/p-coassembled nanowires are approximately 2400 and 10 times more conductive than individual n-type and p-type nanofibers, respectively. This facile strategy allows fabrication of well-defined supramolecular electroactive nanomaterials in aqueous media, which can find a variety of applications in optoelectronics, photovoltaics, organic chromophore arrays, and bioelectronics.

Hierarchical Self‐Assembly of Pyrene‐Linked Cyclodextrin and Adamantane‐Linked Naphthalene Diimide System: A Case of Inclusion‐Binding‐Assisted Charge‐Transfer Interaction

“…A comparison of Figure a with the absorption spectrum of the CT complex (Figure c) suggests that the observed signal (in the 300–420 nm region) is a bisignated CD signal with a first negative cotton effect. Bisignated signal arises due to exciton coupling when the chromophores involved are spatially very close and constitute a chiral system ,. In such a system the electronic transition moments would interact spatially so that the energy levels of the excited states split which will be reflected in the CD spectrum as the bisignated signal.…”

“…For example, Khalily et al . reported the construction of supramolecular 1D nanowires of PY‐NDI system with a high K a value of 5.18 × 10 5 M −1 employing a combination of H‐bonding, CT, and electrostatic interactions, which was the highest K a value reported for the PY‐NDI system so far.…”

Electroactive Amphiphiles for Addressable Supramolecular Nanostructures

“…As discussed at the start of this section, conductivity often depends on the self‐assembled structure of the electroactive materials. The aim is therefore to utilize self‐assembly to improve the co‐facial π‐π interactions and overlap, thereby increasing charge carrier mobilities . Poly‐ and oligo(aniline)s are insulators when prepared in the LEB, EB or PB state.…”

“…An alternative approach to improving conductivity by adding dopants is to mix π‐electron donating and π‐electron accepting materials. Recently, Khalily, M. A. et al . prepared amphiphilic p‐type and n‐type peptides from pyrene and a naphthalenediimide.…”

Peptide‐Driven Charge‐Transfer Organogels Built from Synergetic Hydrogen Bonding and Pyrene–Naphthalenediimide Donor–Acceptor Interactions

“…In this context,U lijn and coworkers reported the biocatalytic self-assembly of NDI-dipeptide conjugates with different donors to give hydrogels. [20] In this paper we report on our successful strategy for the realizationo fC Tsupramolecular gels from the coassembly of Dand A-peptidec onjugates. [18] Finally, Guo and Li reported the forma-tion of CT organogels by coassembly of ap yrene-amino acid conjugate and an NDI.…”