Impact of Polymer-Constrained Annealing on the Properties of DNA Origami-Templated Gold Nanowires

Metallic Nanowires Self-Assembled in Quasi-Circular Nanomolds Templated by DNA Origami

The self-assembly of conducting nanostructures is currently being investigated intensively in order to evaluate the feasibility of creating novel nanoelectronic devices and circuits using such pathways. In particular, methods based on so-called DNA Origami nanostructures have shown great potential in the formation of metallic nanowires. The main challenge of this method is the reproducible generation of very well-connected metallic nanostructures, which may be used as interconnects in future devices. Here, we use a novel design of nanowires with a quasi-circular cross-section as opposed to rectangular or uncontrolled cross-sections in earlier studies. We find indications that the reliability of the fabrication scheme is enhanced and the overall resistance of the wires is comparable to metallic nanostructures generated by electrochemistry or top-down methods. In addition, we observe that some of the nanowires are annealed when passing a current through them, which leads to a clear enhancement for the conductance. We envision that these nanowires provide further steps towards the successful generation of nanoelectronics using self-assembly.

1D Colloidal chains: recent progress from formation to emergent properties and applications

Integrating nanoscale building blocks of low dimensionality (0D; i.e., spheres) into higher dimensional structures endows them and their corresponding materials with emergent properties non-existent or only weakly existent in the individual building blocks. Constructing 1D chains, 2D arrays and 3D superlattices using nanoparticles and colloids therefore continues to be one of the grand goals in colloid and nanomaterial science. Amongst these higher order structures, 1D colloidal chains are of particular interest, as they possess unique anisotropic properties. In recent years, the most relevant advances in 1D colloidal chain research have been made in novel synthetic methodologies and applications. In this review, we first address a comprehensive description of the research progress concerning various synthetic strategies developed to construct 1D colloidal chains. Following this, we highlight the amplified and emergent properties of the resulting materials, originating from the assembly of the individual building blocks and their collective behavior, and discuss relevant applications in advanced materials. In the discussion of synthetic strategies, properties, and applications, particular attention will be paid to overarching concepts, fresh trends, and potential areas of future research. We believe that this comprehensive review will be a driver to guide the interdisciplinary field of 1D colloidal chains, where nanomaterial synthesis, self-assembly, physical property studies, and material applications meet, to a higher level, and open up new research opportunities at the interface of classical disciplines.

DNA Nanotechnology-Enabled Fabrication of Metal Nanomorphology

In recent decades, DNA nanotechnology has grown into a highly innovative and widely established field. DNA nanostructures have extraordinary structural programmability and can accurately organize nanoscale materials, especially in guiding the synthesis of metal nanomaterials, which have unique advantages in controlling the growth morphology of metal nanomaterials. This review started with the evolution in DNA nanotechnology and the types of DNA nanostructures. Next, a DNA-based nanofabrication technology, DNA metallization, was introduced. In this section, we systematically summarized the DNA-oriented synthesis of metal nanostructures with different morphologies and structures. Furthermore, the applications of metal nanostructures constructed from DNA templates in various fields including electronics, catalysis, sensing, and bioimaging were figured out. Finally, the development prospects and challenges of metal nanostructures formed under the morphology control by DNA nanotechnology were discussed.

Bottom-Up Fabrication of DNA-Templated Electronic Nanomaterials and Their Characterization

Bottom-up fabrication using DNA is a promising approach for the creation of nanoarchitectures. Accordingly, nanomaterials with specific electronic, photonic, or other functions are precisely and programmably positioned on DNA nanostructures from a disordered collection of smaller parts. These self-assembled structures offer significant potential in many domains such as sensing, drug delivery, and electronic device manufacturing. This review describes recent progress in organizing nanoscale morphologies of metals, semiconductors, and carbon nanotubes using DNA templates. We describe common substrates, DNA templates, seeding, plating, nanomaterial placement, and methods for structural and electrical characterization. Finally, our outlook for DNA-enabled bottom-up nanofabrication of materials is presented.

Stability Analysis: Rational Design of a Ag Nanoparticle/Polymer Brush for Fabricating Cu Coating on a PET Surface

Excellent stability of a catalytic center would facilitate the prolongation of the cycle of a chemical plating bath and the reduction of environmental pollution. In this study, silane (3-aminopropyltriethoxysilane (KH550) and γ-(2,3-epoxypropoxy)propytrimethoxysilane (KH560)) was incorporated in AgNO₃ solution to rationally prepare a Ag nanoparticle/polymer brush (Ag/PB) catalytic solution. The effects of the KH560 relative content on the Ag/PB structure and stability were studied. The epoxy group in the KH560 could react with an amino group in the KH550 through direct ring-opening reaction to form a secondary amino group and hydroxyl, which could coadsorb Ag nanoparticles by means of a chelating structure; hence, Ag/PB with superior Ag-adsorbed intensity was established on a polyethylene terephthalate (PET) surface. Ag particles on PB with 75% KH560 revealed the best stability of those measured, and the relative Ag surplus was 56.7% after stability testing. The generated Ag/PB that served as catalytic centers to catalyze the electroless copper plating resulted in a facile technology for preparing Cu/PET composite material. This means that the technology has potential application in a green process for preparing metal/polymer composite materials.

Seeding, Plating and Electrical Characterization of Gold Nanowires Formed on Self-Assembled DNA Nanotubes

Self-assembly nanofabrication is increasingly appealing in complex nanostructures, as it requires fewer materials and has potential to reduce feature sizes. The use of DNA to control nanoscale and microscale features is promising but not fully developed. In this work, we study self-assembled DNA nanotubes to fabricate gold nanowires for use as interconnects in future nanoelectronic devices. We evaluate two approaches for seeding, gold and palladium, both using gold electroless plating to connect the seeds. These gold nanowires are characterized electrically utilizing electron beam induced deposition of tungsten and four-point probe techniques. Measured resistivity values for 15 successfully studied wires are between 9.3 × 10-6 and 1.2 × 10-3 Ωm. Our work yields new insights into reproducible formation and characterization of metal nanowires on DNA nanotubes, making them promising templates for future nanowires in complex electronic circuitry.