(Funded by the U.S. National Science Foundation)
Scientists have blended electron microscopy with artificial intelligence (AI) so they can observe the movements of atoms in nanoparticles at an unprecedented time resolution. Because the atoms are usually barely visible in electron microscope images, scientists cannot be sure how they are behaving. So, the scientists in this study trained a deep neural network, AI’s computational engine, that can “light up” the electron-microscope images, revealing the underlying atoms and their dynamic behaviors. “We have developed an artificial-intelligence method that opens a new window for the exploration of atomic-level structural dynamics in materials,” says Carlos Fernandez-Granda, one of the scientists involved in this study.

(Funded by the National Institutes of Health)
Researchers from the University of Illinois Urbana-Champaign have developed organic-material-based nanozymes – synthetic nanomaterials that have enzyme-like catalytic properties – that are non-toxic, environmentally friendly, and cost effective. To create these nanozymes, the researchers used a novel particle synthesis technique that brought each nanozyme’s size down to less than 100 nanometers. In one study, the researchers showed that these nanozymes, combined with a colorimetric sensing platform, could detect the presence of histamine in spinach and eggplant. In another study, the nanozymes were used to detect the presence of glyphosate, a common agricultural herbicide, in plants. “We were able to show that our system doesn’t just work in the lab, it has the potential to be utilized for real-world applications as a cost-effective molecule sensing system for food and agriculture,” said Dong Hoon Lee, lead author of the study.

(Funded by the U.S. National Science Foundation)
Researchers at Northwestern University have created a new platform for monitoring chemical contaminants in the environment. The platform can detect the metals lead and cadmium at concentrations down to two and one parts per billion, respectively, in a matter of minutes. It was created by interfacing nanomechanical microcantilevers with synthetic biology biosensors. When the tiny cantilevers are coated with DNA molecules, biosensing molecules bind to the DNA, causing the cantilevers to bend. When exposed to toxic metals, the biosensors unbind, causing the cantilever to “de-bend,” which can be measured precisely to detect the toxic metals.

(Funded by the U.S. Department of Energy, the U.S. Department of Defense, and the U.S. National Science Foundation)
Researchers from the Molecular Foundry, a user facility at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory, Columbia University, and Universidad Autónoma de Madrid in Spain have developed a new optical computing material from photon-avalanching nanoparticles. This approach offers a path toward realizing smaller, faster components for next-generation computers by taking advantage of intrinsic optical bistability – a property that allows a material to use light to switch between two different states, such as glowing brightly or not at all. For decades, researchers have sought ways to make a computer that uses light instead of electricity. But in previous studies, optical bistability had almost exclusively been observed in bulk materials that were too big for a microchip and challenging to mass produce. Now, the researchers suggest that the new photon-avalanching nanoparticles could overcome these challenges in realizing optical bistability at the nanoscale.

(Funded by the U.S. Department of Energy)
Scientists from the Massachusetts Institute of Technology and the National Institute for Materials Science in Tsukuba, Japan, have discovered that electrons can form crystalline structures in materials composed of either four or five layers of graphene. (Graphene is a one-atom-thick layer of carbon atoms arranged in hexagons, which looks like a honeycomb structure.) Last year, the scientists reported that electrons became fractions of themselves upon applying a current to a material composed of rhombohedral pentalayer graphene and hexagonal boron nitride. This time, the scientists have shown that electrons can become fractions of themselves without a magnetic field. They also found that what they saw last time can be understood to emerge in an electron “liquid” phase, analogous to water, and what they have now observed can be interpreted as an electron “solid” phase that looks like the formation of electronic “ice.”