(Left) Growth of tandem fluorescent fibrils: scale bar = 20µm. (Right) Fibrils extended from gold nanoparticles placed on the surface of a substrate: scale bar = 1µm.
(Left) Growth of tandem fluorescent fibrils: scale bar = 20µm. (Right) Fibrils extended from gold nanoparticles placed on the surface of a substrate: scale bar = 1µm.

A team of researchers from Hokkaido University in Japan has developed a versatile method for patterning the structure of ‘nanowires’, providing a new tool for the development of novel nanodevices.

There has been considerable interest worldwide in the patterning of functionalized nanowires, which can excel both as semiconductors and as catalysts, due to the potential they offer in the next generation of nanodevices. Establishing a versatile approach to making functionalized nanowires and finely controlling their spatial positioning has been seen as essential for these applications.

The team from Hokkaido University, led by Kazuyasu Sakaguchi, a professor in the Department of Chemistry, had previously developed an effective method called structure-controllable amyloid peptides (SCAPs) for controlling the self-assembly of amyloid peptides. In addition to playing a central role in the development of Alzheimer’s disease, amyloid peptides can also be used as building blocks for nanowires.

In this latest research, reported in a paper in Scientific Reports, the team combined SCAPs with templated fibril growth – a distinctive quality of amyloid peptides. This allowed them to fabricate nanowires with tandem domain structures or a single nanowire extending from a specific starting point.

To create the tandem structure, Sakaguchi and his team used the SCAPs method to make initial amyloid fibrils marked with a green fluorescent molecule. They then used these as a template for making another type of amyloid peptide, marked with a red fluorescent molecule, extending from the initial fibrils. Analysis showed a 67% tandem yield, three times higher than the efficiency yield of previous studies. Moreover, a few geometrical patterns could be discerned in the tandem structures, and the proportion of these patterns could be controlled by adjusting the peptide mix ratio.

Furthermore, by attaching template fibrils to gold nanoparticles placed on a substrate surface and then allowing new fibrils to extend from the template fibrils, the researchers were able to fabricate a single nanowire in a specific location. This is the first time this kind of advanced pattern control has been achieved.

According to the researchers, the method is applicable for the self-assembly of nanowires linking nanoelectrodes created by lithography. “It could also be used to prepare a wide variety of fibril patterns and hence open up new avenues for the development of novel self-assembled nanodevices,” said Sakaguchi.

This story is adapted from material from Hokkaido University, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.