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

Researchers from Oregon State University, Oregon Health & Science University, and international collaborators have developed magnetic nanoparticles in the shape of a cube sandwiched between two pyramids for the treatment of ovarian cancer. Made of iron oxide and doped with cobalt, the nanoparticles show exceptional heating efficiency when exposed to an alternating magnetic field. When the particles accumulate in cancerous tissue after intravenous injection, they are able to quickly rise to temperatures that weaken or destroy cancer cells. A cancer-targeting peptide helps the nanoparticles accumulate in the tumor, and because the nanoparticles’ heating efficiency is strong, the necessary concentration of nanoparticles can be achieved without a high dosage, limiting toxicity and side effects.

Researchers at Caltech have developed an on-chip transducer that converts microwave photons to optical photons. The device involves a tiny silicon beam that vibrates at 5 gigahertz and couples to a microwave resonator – essentially a nanoscale box in which photons bounce around, also at 5 GHz. Using a technique called electrostatic actuation, a microwave photon is converted within that box to a mechanical vibration of the beam, and that mechanical oscillation, with the help of laser light, gets converted by the resonator into an optical photon. Such a conversion could enable the construction of large-scale distributed superconducting quantum computers.

Researchers at Cornell University have, for the first time, identified what happens when bacteria receive electrons from quantum dots. Using fluorescence lifetime imaging microscopy with two-photon excitation on a quantum dot and bacteria, the researchers identified a distinct halo surrounding the bacteria, which suggested the charge transfer was receiving some peripheral assistance. It turned out that an electron could either move directly from the quantum dot to the bacterium or be transferred from the bacterium via shuttle molecules. Photosynthetic biohybrids of this sort could potentially convert carbon dioxide into value-added chemical products, such as bioplastics and biofuels, and control other microbial processes. 

By taking two flakes of special materials that are just one atom thick and twisting them at high angles, researchers at the University of Rochester have unlocked unique optical properties that could be used in quantum computers and other quantum technologies. Until now, scientists have explored the optical and electrical properties of 2D materials when layered on top of one another and twisted at very small angles (typically 1.1 degree). In this study, the researchers twisted layers of a 2D material, called molybdenum diselenide, at up to 40 degrees, and found that the resulting structure produced excitons – essentially, artificial atoms – that can act as quantum information bits, or qubits, and can retain information when activated by light. The research was conducted at the University of Rochester’s Integrated Nanosystems Center.

Researchers from the University of Texas at Dallas, the Massachusetts Institute of Technology, and international collaborators have found that rhombohedral graphene behaves similarly to semiconductors and exhibits novel magnetism and superconductivity, as well as the quantum anomalous Hall effect, at extremely low temperatures. Graphene – a single layer of carbon atoms arranged in a flat honeycomb pattern – can be stacked in two different ways: Hexagonal stacking occurs when even-numbered graphene layers are aligned (with the odd-numbered layers rotated 60 degrees relative to the even layers); in contrast, rhombohedral stacking features a unidirectional 60-degree rotation for each successive layer.

Researchers from the University of Connecticut will grow rod-shaped nanoparticles, called Janus base nanotubes, on the International Space Station. These nanotubes will carry interleukin-12, a protein produced naturally by the human body to stimulate the development of helper T-cells, immune cells known for killing pathogens and cancer cells. With cross sections of just 20 nanometers, the nanotubes can slip into the cracks and attack solid tumors from the inside and then release interleukin-12 inside a tumor. Manufacturing these nanotubes in space has many advantages. “Since our nanotubes are self-assembled, there is a lot of similarity to crystallization,” says Yupeng Chen, one of the researchers involved in this study. “Without gravity, there’s no sedimentation, the molecules can rotate and assemble freely, and make better structures.”

Scientists from The Johns Hopkins University, the Mayo Clinic, and Tufts University have developed a potential new way to treat a variety of rare genetic diseases marked by too low levels of specific cellular proteins. To boost those proteins, the scientists created a genetic "tail" that attaches to messenger RNA (mRNA) molecules that churn out the proteins. To deliver these genetic tails, also called “mRNA boosters,” the scientists encased them in nanoparticles covered in lipids. The nanoparticles are naturally absorbed by cells through their fatty outer membranes. After the scientists administered the mRNA boosters to laboratory mice, each group of mice had 1.5 to two times more of the proteins specific to the mRNA boosters than control mice that did not receive the boosters.

Researchers from the University of Rhode Island and Brown University have shown that carbon nanotubes could be combined with machine learning to detect subtle differences between closely related immune cells. The researchers used an in vitro experiment that involved placing live cells into a culture dish, adding carbon nanotubes, and then using a specialized microscope with an infrared camera to observe the emitted light from each cell. The camera generated millions of data points, each of which reflected cellular activity. Healthy cells emitted one type of light, while potentially unhealthy or changing cells emitted different light patterns.

Researchers from Carnegie Mellon University and the University of Southern California have devised a method to create large amounts of a material that can be used to make two-dimensional (2D) semiconductors with record high performance. That material, tellurium, has a fast conducting speed and is stable in the air, so it does not easily degrade. The researchers used 2D tellurium to create an ultralight-weight photodetector – a device that can detect light –  which is highly tunable, allowing its parameters to be changed so it can be used in a variety of applications, a property that is not true of other photodetectors. 

Researchers from Penn State, the University of North Texas, the University of Pennsylvania, Université Paris-Saclay in France, and the National Institute for Materials Science in Tsukuba, Japan, have shown that the light emitted from two-dimensional (2D) materials can be modulated by embedding a second 2D material, called a nanodot, inside them. The researchers showed that by controlling the nanodot size, they could change the color and frequency of the emitted light. The control came from adjusting the band gaps of the materials – essentially the energy threshold electrons must cross to make a material emit light.