Pharmacists at Northwestern University have developed a new photonic system (Nanoparticles enable long-distance communication) with properties never seen before in nature. In solids, the atoms must be equally spaced and close enough together to interact effectively. Now, new structures based on the aggregation of nanoparticles show unprecedented long-distance interactions.
When one lattice is stacked on top of another, the nanoparticles can still interact with each other – even when the vertical separation between the particles is 1,000 times the distance of the particle – without increasing the spacing value in the horizontal plane .
Since nanoparticles can communicate over long distances, the assembled structures offer potential applications in sensing and sensing.
The study was published this week (Feb. 13) in the journal Nature Nanotechnology.
“This kind of long-term correlation has never been seen for anything collected over time,” said study author Teri Odom. “Alternative electronic or photonic space is separated horizontally by a space that is parallel to the vertical phase of the building in one layer. It is a new class of engineering tools that have no parallel or analog in nature.
An expert in nanotechnology, Odom is chair of the chemistry department at Northwestern along with Joan Hustling Madden and William H. Madden Jr. Professor of Chemistry in the Weinberg College of Arts and Sciences. He is also a member of the International Institute of Nanotechnology and the Institute of Chemistry of Life Processes. Northwest authors include George Schatz, Charles E. and Emma H. Morrison Professor of Chemistry at Weinberg.
To design the new material, Odom and his team were inspired by the moiré pattern, a geometric pattern formed by two parallel lattice patterns.
The researchers were the first to fabricate a two-dimensional photonic network of polarized nanoparticles that support vertical integration, resulting in single-layer optics. Next, they collect many similar nanoparticles on top of each other to create two-layer and multi-layer types with new optical properties that cannot be obtained from a single layer.
“We demonstrated that these nanoparticle packaging materials can interact over long distances by placing biological molecules around just one type of nanoparticle in a concentrated form,” Odom said. “Then we are happy with the color.”
The researchers found that by turning one grating in another direction, they could change how the system affects light. Depending on the angle of rotation, this composite material can function as a nanolaser with radiation in different directions. This concept opens new avenues for nano-lasing engineering features. The direction and structure of the moiré laser beam can be directly monitored.
“It can be used to develop new types of biomedical sensors,” said Jun Guan, first author of the paper and a postdoctoral fellow in Odom’s lab. “These devices can be designed to react to changes in the body, providing important information about the patient’s health. Small changes in the chemistry of the blood environment can cause changes in the way light travels around the photonic network. This variable will be updated from the moiré pattern and read from the corresponding laser beam angle.
