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

Flexible color displays with microfluidics

August 16, 2018

A new study published on Microsystems and Nanoengineering by Kazuhiro Kobayashi and Hiroaki Onoe details the development of a flexible and reflective multicolor display system that does not require continued energy supply ...

Twisted electronics open the door to tunable 2-D materials

August 16, 2018

Two-dimensional (2-D) materials such as graphene have unique electronic, magnetic, optical, and mechanical properties that promise to drive innovation in areas from electronics to energy to materials to medicine. Columbia ...

Novel sensors could enable smarter textiles

August 16, 2018

A team of engineers at the University of Delaware is developing next-generation smart textiles by creating flexible carbon nanotube composite coatings on a wide range of fibers, including cotton, nylon and wool. Their discovery ...

Scientists discover why silver clusters emit light

August 16, 2018

Clusters of silver atoms captured in zeolites, a porous material with small channels and voids, have remarkable light-emitting properties. They can be used for more efficient lighting applications as a substitute for LED ...

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.