One‐Dimensional Gold Nanoparticle Arrays by Electrostatically Directed Organization Using Polypeptide Self‐Assembly

Abstract

The study of interactions between particles organized in a linear configuration is interesting from a quantum mechanical perspective, and the anisotropic properties of linear assemblies is of potential interest for the development of solid-state devices. [1][2][3] This anisotropy may be manifested as a difference in the magnetization and coercivity obtained in a magneticnanoparticle array when a field is applied along the chain or orthogonal to it. [4,5] Nonlinear electrical characteristics [3] or dichroism in the optical spectra with longitudinal and transverse polarizations of light [6,7] in metal nanoparticle arrays are other examples of such anisotropy, and the construction of such arrays would offer opportunities in multiple applications. Engineering matter at submicron length scales has been an area largely dominated by top-down methodologies. Control of interparticle spacing in metal-nanoparticle arrays by using techniques such as electron beam lithography has been found to have a dramatic impact on the optical response of the nanoparticle assembly, [8][9][10] and has implications in fields such as plasmonics [11] and energy transport. [12,13] The use of templates such as carbon nanotubes [14] and linear pores [15] to construct one-dimensional nanostructures has been demonstrated previously. In addition, polymers have recently begun to play an increasingly active role as elements that can reproducibly direct the arrangement of nanoparticles into functional geometries. [16,17] Self assembling systems offer convenient yet powerful bottom-up strategies for the creation of nanostructures that can be deployed in the realization of functional nanoscale devices. [18,19] The utilization of biomolecules such as DNA, [3,[20][21][22][23][24] and protein-based materials [25][26][27] or viruses [28,29] to dictate the organization of nanoparticles has been shown to be an effective and robust paradigm. The use of peptide-based structures [30,31] in nanotechnology confers numerous advantages such as the specification of assembled nanostructure by changes in the primary sequence of the peptide, as well as the adoption of various hierarchical morphologies in solution. [32][33][34][35] This approach consequently permits the engineering of chemical functionality at precise positions in the nanoarchitecture of the assembled morphology. This functionality can be highly selective toward the binding of different inorganic materials [36] and may be engineered for biological recognition.[37] Herein, we demonstrate the construction of one-dimensional gold nanoparticle arrays with precise axial separations using self-assembling polypeptide fibrils. We elucidate the self-assembly of an alanine-rich polypeptide (designated 17H6) into fibrils that present regularly spaced charged patches along the fibril length. These positively charged patches are then utilized for the electrostatic binding of oppositely charged inorganic nanoparticles, thus resulting in linear nanoparticle arrays. The nanoparticles are immobilized on the fibril templa...

Impact of multivalent charge presentation on peptide–nanoparticle aggregation

“…Since the oligomerization state of VW05 has been studied before [30], the DLS spectrum of VW05 was used as a reference for all other peptides. All measurements were performed at a sample concentration of 15 µM at pH 9 and pH 11 because the net charge of the peptides switches from positive to negative within this pH range.…”

Controlling assembly of helical polypeptides via PEGylation strategies

“…It was also shown that the histidine tag plays a solubilizing role when it is charged, in addition to its conventional function in protein purification and its observed role in the immobilization of negatively charged nanoparticles. 81 At acidic pH (upon protonation of glutamic acid residues), the polypeptide and the conjugates formed aggregates with elongated or spherical morphologies depending on the nature and length of the hydrophilic block. Although only a few examples were shown in this study, our results clearly illustrate that a combination of recombinant synthesis and chemical conjugation methods may offer a wide spectrum of nanostructures with controlled size and morphology by the precise control of the block composition.…”

Selective Hybridization of Dendron-Cyclodextrin Nanotubes with Metal Nanoparticles

“…5,9,11 In particular, fabrication of linear assemblies of inorganic elements is of great interest for the development of nano-devices due to their anisotropic properties in 1-dimensional state. 16 For that purpose, carbon nanotubes are excellent template for the fabrication of linear assembly of inorganic elements. 17,18 In addition, biomolecules such as DNA, 19 peptides, 16 and viruses 20 were used as a template for the organization of nanoparticles.…”

“…16 For that purpose, carbon nanotubes are excellent template for the fabrication of linear assembly of inorganic elements. 17,18 In addition, biomolecules such as DNA, 19 peptides, 16 and viruses 20 were used as a template for the organization of nanoparticles. Self-assembled organic nanotubes are particularly advantageous as a template for the linear organization of nanoparticles because the surface anchoring functionality can be efficiently tailored.…”

“…[4][5][6][7][8][9][10][11][12] In addition, the electronic or chemical communication between organic and inorganic moieties would provide an opportunity to produce unique functional hybrids. 13,14 In particular, organic nanotubes have attracted considerable attention as a template for nanohybrids, 3,15,16 for examples, lipid nanotubes for the template of silica 3,15 and peptide nanofibers for the template of biomineralization. 5,9,11 In particular, fabrication of linear assemblies of inorganic elements is of great interest for the development of nano-devices due to their anisotropic properties in 1-dimensional state.…”