Nav: Home

Self-assembled nanostructures can be selectively controlled

April 24, 2017

Plasmonic nanoparticles exhibit properties based on their geometries and relative positions. Researchers have now developed an easy way to manipulate the optical properties of plasmonic nanostructures that strongly depend on their spatial arrangement.

The plasmonic nanoparticles can form clusters, plasmonic metamolecules, and then interact with each other. Changing the geometry of the nanoparticles can be used to control the properties of the metamolecules.

"The challenge is to make the structures change their geometry in a controlled way in response to external stimuli. In this study, structures were programmed to modify their shape by altering the pH," tells Assistant Professor Anton Kuzyk from Aalto University.

Utilization of programmable DNA locks

In this study plasmonic metamolecules were functionalized with pH-sensitive DNA locks. DNA locks can be easily programmed to operate at a specific pH range. Metamolecules can be either in a "locked" state at low pH or in relaxed state at high pH. Both states have very distinct optical responses. This in fact allows creating assemblies of several types of plasmonic metamolecules, with each type designed to switch at different a pH value.

The ability to program nanostructures to perform a specific function only within a certain pH window could have applications in the field of nanomachines and smart nanomaterials with tailored optical functionalities.

This active control of plasmonic metamolecules is promising for the development of sensors, optical switches, transducers and phase shifters at different wavelengths. In the future, pH-responsive nanostructures could also be useful in the development of controlled drug delivery.
-end-
The study was carried out by Anton Kuzyk from Aalto University, Maximilian Urban and Na Liu from Max Planck Institute for Intelligent Systems and the Heidelberg University, and Andrea Idili and Francesco Ricci from the University of Rome Tor Vergata.

More information:

Anton Kuzyk
Assistant Professor
Aalto University
anton.kuzyk@aalto.fi
tel. +358 50 443 0492

Article: Selective control of reconfigurable chiral plasmonic metamolecules http://advances.sciencemag.org/content/3/4/e1602803

Aalto University

Related Nanoparticles Articles:

Study models new method to accelerate nanoparticles
In a new study, researchers at the University of Illinois and the Missouri University of Science and Technology modeled a method to manipulate nanoparticles as an alternative mode of propulsion for tiny spacecraft that require very small levels of thrust.
Actively swimming gold nanoparticles
Bacteria can actively move towards a nutrient source -- a phenomenon known as chemotaxis -- and they can move collectively in a process known as swarming.
Nanoparticles take a fantastic, magnetic voyage
MIT engineers have designed tiny robots that can help drug-delivery nanoparticles push their way out of the bloodstream and into a tumor or another disease site.
Quantum optical cooling of nanoparticles
One important requirement to see quantum effects is to remove all thermal energy from the particle motion, i.e. to cool it as close as possible to absolute zero temperature.
Nanoparticles help realize 'spintronic' devices
For the first time researchers have demonstrated a new way to perform functions essential to future computation three orders of magnitude faster than current commercial devices.
More Nanoparticles News and Nanoparticles Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...