(Funded by the U.S. Department of Energy and the U.S. National Science Foundation)
Researchers from the U.S. Department of Energy’s (DOE) Oak Ridge National Laboratory (ORNL), Purdue University, and the University of Illinois Urbana−Champaign have used a nanoscale quantum sensor to measure spin fluctuations near a phase transition in a magnetic thin film. Thin films with magnetic properties at room temperature are essential for data storage, sensors and electronic devices because their magnetic properties can be precisely controlled and manipulated. The researchers used a specialized instrument called a scanning nitrogen-vacancy center microscope at the Center for Nanophase Materials Sciences, a DOE Office of Science user facility at ORNL. A nitrogen-vacancy center is an atomic-scale defect in diamond in which a nitrogen atom takes the place of a carbon atom, and a neighboring carbon atom is missing, creating a special configuration of quantum spin states.

(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.