News from the NNI Community - Research Advances Funded by Agencies Participating in the NNI

Researchers from Vanderbilt University have developed advanced dialysis membranes using an atomically thin material called graphene. These innovative membranes leverage a protein-enabled sealing mechanism that works as follows: When proteins escape through larger pores, they react with molecules on the other side of the graphene membrane. This reaction triggers a sealing process, selectively closing larger pores while preserving smaller ones. This self-sealing capability ensures precise size-selective filtration and improves the membrane's overall effectiveness. The defect-sealed membranes remained stable for up to 35 days and consistently outperformed state-of-the-art commercial dialysis membranes. 

Researchers from the Joint Institute for Laboratory Astrophysics (JILA) (a joint institute of the University of Colorado Boulder and the National Institute of Standards and Technology), KMLabs Inc. in Boulder, CO, and 3M Center in St. Paul, MN, have developed a novel microscope that makes examining ultrawide-bandgap semiconductors – which have a relatively large energy gap between the valence and conduction bands – possible on an unprecedented scale. The microscope uses high-energy deep ultraviolet laser light to create a nanoscale interference pattern on the material's surface, heating it in a controlled, periodic pattern. Observing how this pattern fades over time provides insights into the electronic, thermal, and mechanical properties at spatial resolutions as fine as 287 nanometers, well below the wavelength of visible light.

A new experimental vaccine developed by researchers from the Massachusetts Institute of Technology, Massachusetts General Hospital, Caltech, and the University of Cambridge in the United Kingdom could offer protection against emerging variants of SARS-CoV-2, as well as related coronaviruses, known as sarbecoviruses, that could spill over from animals to humans. Sarbecoviruses include SARS-CoV-2 (the virus that causes COVID-19) and the virus that led to the outbreak of the original SARS in the early 2000s. By attaching up to eight different versions of sarbecovirus receptor-binding proteins to nanoparticles, the researchers created a vaccine that generates antibodies that recognize regions of receptor-binding proteins that tend to remain unchanged across all strains of the viruses.

Scientists from Montana State University, Columbia University, the Massachusetts Institute of Technology, Pennsylvania State University, North Carolina State University, the Honda Research Institute in San Jose, CA, and the National University of Singapore have enabled the emission of single photons of light in ultra small, two-dimensional, ribbon-shaped materials measuring one atom thick and tens of atoms wide – about a thousand times narrower than the width of a human hair. Although the ability to emit single photons was known to occur in large sheets of two-dimensional materials, the observation made in this study is the first demonstration that the ability to emit single photons also occurs in much smaller ribbon structures. 

Scientists from the U.S. Food and Drug Administration, Northwestern University, and the Illinois Institute of Technology have found evidence that silver nanoparticles embedded in packaging used as an antimicrobial agent were able to seep into the dry food the packaging is meant to protect. The scientists created samples of silver nanoparticles and embedded them in polyethylene film wraps, which could hold various types of food items. They tested wheat flour, slices of cheese, ground rice, and spinach leaves. They found that the nanoparticles had made their way to all the foods, though to varying degrees. They found, for example, that there was far more contamination of the cheese than there was of the spinach leaves.

University of Missouri scientists are unlocking the secrets of halide perovskites – a material that might bring us closer to energy-efficient optoelectronics. The scientists are studying the material at the nanoscale. At this level, the material is astonishingly efficient at converting sunlight into energy. To optimize the material for electronic applications, the scientists used a method called ice lithography, known for its ability to fabricate materials at the nanometer scale. This ultra-cool method allowed the team to create distinct properties for the material using an electron beam. 

Measuring temperature and humidity in a variety of crop-growing circumstances has prompted the development of numerous sensors, but ensuring these devices are effective while remaining environmentally friendly and cost-effective is a challenge. Now, researchers at Auburn University in Alabama have developed paper-based temperature and humidity sensors that are accurate and reliable, as well as eco-friendly. The researchers created the sensors by printing silver lines on four types of commercially available paper through a process called dry additive nanomanufacturing. The sensors successfully detected changes in relative humidity levels from 20% to 90% and temperature variations from 25°C to 50°C. 

Researchers from Case Western Reserve University, the University of Illinois Urbana-Champaign, Adamas Nanotechnologies (Raleigh, NC), the University of Luxembourg in Luxemburg, Umeå University in Sweden, and Aix Marseille University in France have found that boron-doped diamonds exhibit plasmons – waves of electrons that move when light hits them – allowing electric fields to be controlled and enhanced on a nanometer scale. Previously, boron-doped diamonds were known to conduct electricity and become superconductors, but not to have plasmonic properties. Plasmonic materials, which affect light at the nanoscale, have captivated humans for centuries. For example, the vibrant colors in medieval stained-glass windows result from metal nanoparticles embedded in the glass, and when light passes through, these nanoparticles generate plasmons that produce specific colors.

Researchers from Northwestern University, Duke University, and Cornell University have developed the first two-dimensional mechanically interlocked material. Looking like the interlocking links in chainmail, the nanoscale material exhibits exceptional flexibility and strength. With further work, this material holds promise for use in high-performance, light-weight body armor and other uses that demand lightweight, flexible, and tough materials. "We made a completely new polymer structure," said William Dichtel, the study's corresponding author. "It's similar to chainmail in that it cannot easily rip because each of the mechanical bonds has a bit of freedom to slide around. If you pull it, it can dissipate the applied force in multiple directions. And if you want to rip it apart, you would have to break it in many, many different places.”

Researchers from the University of Pennsylvania; the Wistar Institute in Philadelphia, PA; Central South University in Changsha, China, have engineered small nano-sized capsules called extracellular vesicles from human cells to target a cell-surface receptor called DR5 (death receptor 5) that many tumor cells have. When activated, DR5 can trigger the death of these tumor cells by a self-destruct process called apoptosis. Researchers have been trying for more than 20 years to develop successful DR5-targeting cancer treatments. The new approach outperformed DR5-targeting antibodies, which have been considered a leading DR5-targeting strategy. The small extracellular vesicles efficiently killed multiple cancer cell types in lab-dish tests and blocked tumor growth in mouse models, enabling longer survival than DR5-targeting antibodies.