Building miniature optical antennas using DNA as a guide

February 2, 2018, Aalto University
DNA assisted lithography: bowtie-shaped DNA origami is transformed into a metallic nanostructure. Credit: M. Kostiainen

An international research collaborative has reported a new, highly parallel technique to fabricate precise metallic nanostructures with designed plasmonic properties by means of self-assembled DNA origami shapes. The so-called DALI (DNA-assisted lithography) method has been published in the latest issue of Science Advances.

"We can build virtually any nanoscale shape using a DNA origami technique, and now we have shown how to use these accurate shapes as "stencils" to create millions of fully metallic nanostructures with 10 nm feature sizes in one go," explains Adjunct Professor Veikko Linko from Aalto University. The trick in the DALI is that when the DNA structures are deposited on a chip coated with silicon, silicon oxide can be selectively grown only on the bare areas of the substrate. "By controlling this process, we can create origami-shaped openings on the grown layer, and this layer can be used as a mask for the following lithography steps. Finally, we evaporate metal through these openings and create metallic structures having the same shape and size as the original DNA origami on a , such as sapphire," Boxuan Shen from the Nanoscience Center of University of Jyväskylä describes the method.

The tiny metallic features cover the whole transparent substrate, and therefore these surfaces have intriguing optical properties. The small dimensions of the structures—in the range of 10 nanometers—allow further tuning of these properties at the visible wavelength range. "Actually, we have demonstrated here a that we believe is the world's smallest entirely metallic bowtie-shaped antenna. This extremely small size extends the operating range of optical features from infrared to visible," says Adjunct Professor Jussi Toppari from the University of Jyväskylä. These antennas have dozens of optical and plasmonic applications, such as enhanced Raman spectroscopy, biosensing or fluorescence enhancement. Moreover, the researchers demonstrated that the surfaces can be used as polarizers by fabricating chiral structures using DALI.

DNA assisted lithography. Credit: M. Kostiainen and V. Linko

"The DALI method is highly parallel, and it could further enable cheap wafer-scale production of surfaces as it does not rely on costly patterning methods. It is also equipped for the future studies to provide bioinspired surfaces and metamaterials if the customized origami structures can be arranged on the substrate before metallization," says Professor Mauri Kostiainen from the Biohybrid Materials Group at Aalto University.

Explore further: Realizing highly efficient quantum dot LEDs with metallic nanostructures at low cost

More information: Plasmonic nanostructures through DNA-assisted lithography , Science Advances (2018). DOI: 10.1126/sciadv.aap8978 , http://advances.sciencemag.org/content/4/2/eaap8978

Related Stories

'Origami' lattices with nano-scale surface ornaments

December 1, 2017

Inspired by origami, the Japanese art of paper folding, researchers at TU Delft are developing an alternative to 3-D printing that gives the final products many more functionalities than what is possible with 3-D printing. ...

DNA nanostructures get camouflaged by proteins

October 6, 2017

Researchers from Aalto University and Helsinki University have reported a strategy that significantly increases the stability of DNA nanostructures against DNA digesting enzymes, enhances delivery rates and, most importantly, ...

Recommended for you

A soft solution to the hard problem of energy storage

May 18, 2018

It's great in the lab, but will it actually work? That's the million-dollar question perpetually leveled at engineering researchers. For a family of layered nanomaterials, developed and studied at Drexel University—and ...

New blood test rapidly detects signs of pancreatic cancer

May 17, 2018

Pancreatic cancer is expected to become the second deadliest cancer in the United States by 2030. It is tough to cure because it is usually not discovered until it has reached an advanced stage. But a new diagnostic test ...

Metallic drivers of Alzheimer's disease

May 17, 2018

X-ray spectromicroscopy at the Scanning X-ray Microscopy beamline (I08), here at Diamond, has been utilised to pinpoint chemically reduced iron and calcium compounds within protein plaques derived from brains of Alzheimer's ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.