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

Researchers from The Johns Hopkins University and the University of Science and Technology of China in Hefei have created nanoprobes that light up when they encounter certain enzymes found in cancer cells. The ability to visualize tumors early could significantly enhance cancer imaging, inform treatment options, and improve patient outcomes. Currently, tissue biopsies are the gold standard for detecting most cancers, but they can miss parts of tumors lurking in the margins. 

Researchers at the University of Minnesota, Twin Cities, have found that radiation from electron beams can repair cracks in nanostructures. "What we showed … is that when we took a crystal of titanium dioxide and irradiated it with an electron beam, the naturally occurring narrow cracks actually filled in and healed themselves," said Andre Mkhoyan, the lead researcher in this study. In the self-healing process, several atoms of the crystal moved together in tandem, met in the middle, and formed a sort of bridge that filled the crack. 

UCLA researchers have developed a new treatment method using tiny nanocapsules to help boost the immune response, making it easier for the immune system to fight and kill solid tumors. Cancer cells produce a lot of lactate, which creates an environment around the solid tumor that makes it difficult for the immune system to work effectively against the cancer. So, the researchers developed a treatment encapsulating an enzyme, called lactate oxidase, into a tiny nanocapsule that reduces lactate levels and releases hydrogen peroxide, a chemical that helps recruit and activate immune cells in tumors.

Researchers from the National Institute of Standards and Technology (NIST); the University of Nevada, Reno; George Mason University; and the National Institute for Materials Science in Tsukuba, Japan, have developed a “quantum ruler” to measure and explore the properties of twisted layers of graphene. Graphene is a single-atom-thick sheet of carbon atoms that looks like chicken wire. This work may lead to a new, miniaturized standard for electrical resistance that could calibrate electronic devices directly on the factory floor, eliminating the need to send them to an off-site standards laboratory.

Taste receptors on the human tongue convert chemical data into electrical impulses. These impulses are then sent through neurons to the brain's gustatory cortex, where an intricate network of neurons in the brain shapes our perception of taste. Now, researchers at Penn State have developed an electronic “tongue” and an electronic “gustatory cortex” made with 2D materials, which are materials one-to-a-few atoms thick. The artificial tastebuds comprise tiny, graphene-based electronic sensors that can detect gas or chemical molecules. 

University of Massachusetts Amherst researchers have developed a new method for DNA detection with unprecedented sensitivity. The test sample is put within an alternating electric field, causing the DNA strands, which are tethered to a graphene transistor, to oscillate at a specific oscillation frequency. The researchers then read the collected data to see if there is a molecule moving in a way that matches the movement of the target DNA, easily distinguishing it from other molecules in the sample. 

Researchers at the U.S. Department of Energy’s Sandia National Laboratories have combined earlier work on painless microneedles with nanoscale sensors to create a wearable sensor patch that can continuously monitor the levels of an antibiotic called vancomycin. Continuous monitoring is crucial for vancomycin, because there is a narrow range within which it effectively kills bacteria without harming the patient, said Alex Downs, one of the scientists involved in this study.

Caltech researchers have developed a wearable sensor that monitors estradiol by detecting its presence in sweat. Estradiol is a hormone that is necessary for the development of secondary sexual characteristics in women and regulates their reproductive cycles. The sensor is built on a flexible plastic membrane; has tiny etched passages for channeling small amounts of sweat into the sensor; and is made with inkjet-printed gold nanoparticles and titanium carbide films (known as MXenes) that give the sensor a large surface area and electrical conductivity to increase its sensitivity.

Researchers from the University of Illinois Urbana-Champaign and the University of California, Irvine, have discovered that the friction on a graphene surface can be dynamically tuned using external electric fields. Surfaces coated in graphene films generally exhibit very low friction, but the new results demonstrate that friction on graphene-coated surfaces can be "turned on" by exposing the surface to an electric field under the proper conditions. The system can then be switched back to lower friction without applying large electrical biases between the surfaces in contact.

Scientists from Columbia University, the University of Connecticut, and the Center for Functional Nanomaterials, a user facility at the U.S. Department of Energy’s Brookhaven National Laboratory, have created a pure form of glass coated with specialized pieces of DNA; the resulting material was not only stronger than steel but also incredibly lightweight. The scientists used a very thin layer of silica glass, only about 5 nanometers, or a few hundred atoms thick, to coat the DNA frames, leaving inner spaces open and ensuring that the resulting material is ultra-light. To measure the strength of these tiny structures, the scientists  used a technique, called nanoindentation, which is  performed using a precise instrument that can apply and measure resistive forces. When put to the test, the glass-coated DNA lattice was shown to be four times stronger than steel, and its density was about five times lower.