Self-assembled nanostructures can be selectively controlled
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.
鈥淭he 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,鈥 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 鈥渓ocked鈥 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.
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:
Read more news
Samu Taulu develops next-generation brain imaging methods
Associate Professor of neurostimulation and neuroimaging Samu Taulu develops more precise methods for understanding the brain
EAA Best Paper and Presentation Award for Young Researchers for postdoctoral researcher Thomas Deppisch
The awarded work shows how speech can be made clearer in noisy environments while still preserving directional cues
Professor Hanna Maylett: 鈥淲ithout time spent together, a shared vision cannot emerge鈥
According to Hanna Maylett, associate professor of film directing, a director doesn鈥檛 need to know all the answers; rather, their role is to create a process through which those answers can be discovered together.