Laterally Spaced Linear Nanoparticle Arrays Templated by Laminated β‐Sheet Fibrils

Abstract

The ability to precisely arrange molecules or particles on the nanometer scale is an opportunity approached from many experimental perspectives. Molecular self-assembly is particularly promising for "bottom-up" nanofabrication because of its versatility and potential ease to pattern features on the nanometer size scale unavailable with conventional "top-down" (e.g., lithography) methods. Facile control of the size, shape, and spatial distribution of nanoparticles, proteins, and biomolecules creates opportunities with applications in fields ranging from nanoelectronics to biosensing. In a recent review, Kotov et al. described particular interest in one-dimensional nanostructures constructed by the linear assembly of inorganic nanoparticles because of the interparticle electronic, photonic, and energy transfer properties which give rise to potential device applications as well as provide model systems for the fundamental understanding of interparticle nanometer-scale phenomena.[1] Currently, there are a variety of solution-based assembly strategies being explored for the fabrication of linear inorganic nanoparticle assemblies. Most of these solution assembly strategies involve the use of a linear template such as polymers [2] or carbon nanotubes.[3] Biological molecules offer great potential for use in such applications because of the complexity of nanostructures they can inherently form and the ability to design multiple types and numbers of interactions within the same molecule. [4,5] DNA is a widely used template and has been shown by Seeman [6][7][8] and others [9][10][11][12][13] to be useful as a programmable two-dimensional template for the organization of inorganic nanoparticle arrays. Protein-based materials such as collagen, [14] microtubules, [15] amyloid fibrils, [16] viruses, [17][18][19] and de novo designed peptide assemblies [20][21][22][23][24] are a few examples of linear templates used for constructing 1D nanoparticle assemblies. Despite the diversity of templates employed thus far, most attempts, with the exception of DNA, have resulted in linear nanoparticle assemblies without specific control over relative particle placement. In this Communication, we demonstrate the ability of a de novo designed peptide-based template, formed through simple solution-based self-assembly and exhibiting a unique nontwisted, laminated morphology, [25] to produce periodically spaced, parallel, linear nanoparticle arrays. Research in the Pochan and Schneider groups has focused on the design of peptides and the understanding of their selfassembly behavior for biomaterials applications in tissue engineering as well as the current interest in construction of peptide-inorganic hybrid materials for potential nanotechnology applications. [25][26][27][28][29][30] Synthetic peptides can be designed to adopt specific secondary conformations, such as an a-helix or b-sheet, by utilization of specific design motifs. In turn, intermolecular interactions can be utilized to direct the formation of complex, hierarchical assemblies...

Bio-inspired supramolecular self-assembly towards soft nanomaterials

“…To harness the potential of inorganic nanoparticles as building blocks, scientists have devised various approaches to assemble inorganic nanoparticles into one-, two-, and three-dimensional hierarchical architectures [162–164]. For example, Fenniri et al used self-assembled rosette nanotubes (RNTs) which are a new class of biocompatible materials obtained through self-assembly of G∧C motif, to nucleate and assemble monodisperse gold nanoparticles [165].…”

“…For example, Fenniri et al used self-assembled rosette nanotubes (RNTs) which are a new class of biocompatible materials obtained through self-assembly of G∧C motif, to nucleate and assemble monodisperse gold nanoparticles [165]. Pochan et al have prepared nanosheets of gold nanoparticles, in which laminated β-sheet peptide fibrils acted as templates, and negatively charged gold nanoparticles intercalated within fibril laminates [164]. The formation of the aggregates was induced by electrostatic interactions with the positively charged lysine side chains of the fibrils.…”

Peptide‐Based Biomimetic Materials

“…In particular, their inherent biological originality and important roles played in biomineralization make them attractive in the design and creation of a variety of inorganic nanoparticle superstructures, including one -dimensional nanoparticle chains [138 -140] , two -dimensional nanoparticle sheets [141] , three -dimensional nanoparticle spheres [142 -144] , and nanoparticle double helices [145] . In particular, their inherent biological originality and important roles played in biomineralization make them attractive in the design and creation of a variety of inorganic nanoparticle superstructures, including one -dimensional nanoparticle chains [138 -140] , two -dimensional nanoparticle sheets [141] , three -dimensional nanoparticle spheres [142 -144] , and nanoparticle double helices [145] .…”

“…By using a similar strategy, the group of Pochan and Schneider constructed two -dimensional sheets of gold nanoparticles adopting self -assembled nontwisted laminated β -sheet peptide fi brils as temples [141] . De novo designed peptide, (VK) 4 -VPPT -(KV) 4 , was used to assemble laminated β -sheet fi brils consisting of alternating layers of hydrophobic valine residues and hydrophilic lysine residues ( Figure 6.20 ).…”

“…Such a unique peptide nanostructure is suitable for use as a nanoscale template. The ordered organization of nanoparticles on the two -dimensional sheets was predominately ascribed to the electrostatic interaction between negatively charged particles with the positively charged lysine residues, but was affected by multiple factors such as the nontwisted laminated morphology of a template, strong complementary interaction, and the same order between particle size and lateral spacing of the fi bril [141] . The ordered organization of nanoparticles on the two -dimensional sheets was predominately ascribed to the electrostatic interaction between negatively charged particles with the positively charged lysine residues, but was affected by multiple factors such as the nontwisted laminated morphology of a template, strong complementary interaction, and the same order between particle size and lateral spacing of the fi bril [141] .…”