(Funded by the U.S. National Science Foundation and the U.S. Department of Energy)
Scientists from the U.S. Department of Energy’s (DOE) Argonne National Laboratory (ANL) and SLAC National Accelerator Laboratory; the University of Chicago; the University of Vermont; Middlebury College; Brown University; Stanford University; and Northwestern University have observed that when semiconductor nanocrystals called quantum dots were exposed to short bursts of light, the symmetry of the crystal structure changed from a disordered state to a more organized one. The return of symmetry directly affected the electronic properties of the quantum dots by causing a decrease in the bandgap energy, which is the difference in energy that electrons need to jump from one state to another within a semiconductor material. This change can influence how well quantum dots conduct electricity and respond to electric fields. Part of this work was conducted at the Center for Nanoscale Materials, a DOE Office of Science user facility at ANL.

(Funded by the U.S. National Science Foundation)
Researchers at The Ohio State University have developed a new material that, by harnessing the power of sunlight, can clear water of dangerous pollutants. Solar fuel systems that use titanium dioxide nanoparticles can cause significant challenges to implementation, including low efficiency and the need for complex filtration systems. So, the researchers added copper to the nanoparticles, and the new structures, called nanomats, can now absorb enough light energy to break down harmful pollutants in air and water. These lightweight, easy-to-remove fiber mats can float and operate atop any body of water and are even reusable through multiple cleaning cycles. Because the nanomats are so effective, the researchers envision that they could be used to rid water of industrial pollutants in developing countries, turning otherwise contaminated rivers and lakes into sources of clean drinking water.

(Funded by the National Institutes of Health)
Scientists from The Wistar Institute, the University of Pennsylvania, the Icahn School of Medicine at Mount Sinai, Saint Joseph’s University (Philadelphia, PA), and Inovio Pharmaceuticals (Plymouth Meeting, PA) have described a next-generation vaccination technology that combines plasmid DNA with a lipid nanoparticle delivery system. The team showed that these DNA lipid nanoparticles demonstrate a unique way of priming the immune system compared to mRNA and protein-in-adjuvant formulations and that these DNA lipid nanoparticles induced robust antibody and T-cell responses after a single dose. Importantly, these responses were durable, with memory responses in small animals persisting beyond a year after immunization.

(Funded by the National Institutes of Health)
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.

(Funded by the U.S. Department of Defense and the U.S. National Science Foundation)
Researchers from the City University of New York, Yale University, Caltech, Kansas State University, and international collaborators have discovered a new way of generating phonon-polaritons, a unique type of electromagnetic wave that occurs when light interacts with vibrations in a material’s crystal lattice structure. This advance could pave the way for cheaper, smaller long-wave infrared light sources and more efficient device cooling. The researchers made that discovery by using a thin layer of graphene sandwiched between two hexagonal boron nitride slabs. Until now, exciting and detecting phonon-polariton waves has been expensive – typically involving costly mid-infrared or terahertz lasers and near-field scanning probes – but in this study, the researchers used a cheaper alternative: an electrical current generated by applying an electric field to the graphene.