In a recent paper,* the team led by NIST chemist Bryant C. Nelson showed that under laboratory conditions, cupric oxide nanoparticles have the capacity to enter plant root cells and generate many mutagenic DNA base lesions.
The team tested the man-made, ultrafine particles between 1 and 100 nanometers in size on a human food crop, the radish, and two species of common groundcovers used by grazing animals, perennial and annual ryegrass. This research is part of NIST's work to help characterize the potential environmental, health and safety (EHS) risks of nanomaterials, and develop methods for identifying and measuring them.
Cupric oxide (also known as copper (II) oxide or CuO) is a compound that has been used for many years as a pigment for coloring glass and ceramics, as a polish for optics, and as a catalyst in the manufacture of rayon. Cupric oxide also is a strong conductor of electric current, a property enhanced at the nanoscale level, which makes the nanoparticle form useful to semiconductor manufacturers.
Because cupric oxide is an oxidizing agent—a reactive chemical that removes electrons from other compounds—it may pose a risk. Oxidation caused by metal oxides has been shown to induce DNA damage in certain organisms. What Nelson and his colleagues wanted to learn was whether nanosizing cupric oxide made the generation and accumulation of DNA lesions more or less likely in plants. If the former, the researchers also wanted to find out if nanosizing had any substantial effects on plant growth and health.
To obtain the answers, the NIST/UMass researchers first exposed radishes and the two ryegrasses to both cupric oxide nanoparticles and larger sized cupric oxide particles (bigger than 100 nanometers) as well as to simple copper ions. They then used a pair of highly sensitive spectrographic techniques** to evaluate the formation and accumulation of DNA base lesions and to determine if and how much copper was taken up by the plants.
For the radishes, twice as many lesions were induced in plants exposed to nanoparticles as were in those exposed to the larger particles. Additionally, the cellular uptake of copper from the nanoparticles was significantly greater than the uptake of copper from the larger particles. The DNA damage profiles for the ryegrasses differed from the radish profiles, indicating that nanoparticle-induced DNA damage is dependent on the plant species and on the nanoparticle concentration.
Finally, the researchers showed that cupric oxide nanoparticles had a significant effect on growth, stunting the development of both roots and shoots in all three plant species tested. The nanoparticle concentrations used in this study were higher than those likely to be encountered by plants under a typical soil exposure scenario.
"To our knowledge, this is first evidence that there could be a 'nano-based effect' for cupric oxide in the environment where size plays a role in the increased generation and accumulation of numerous mutagenic DNA lesions in plants," Nelson says.Next up for Nelson and his colleagues is a similar study looking at the impact of titanium dioxide nanoparticles—such as those used in many sunscreens—on rice plants.
** Gas chromatography–mass spectrometry (GC-MS) to detect base lesions and inductively coupled plasma mass spectrometry (ICP-MS) to measure copper uptake.
Michael E. Newman | EurekAlert!
Deep decarbonization of industry is possible with innovations
25.03.2019 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)
Five-point plan to integrate recreational fishers into fisheries and nature conservation policy
20.03.2019 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.
The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...
Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.
The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...
Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.
Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...
The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.
A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...
Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.
"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...
11.03.2019 | Event News
01.03.2019 | Event News
28.02.2019 | Event News
25.03.2019 | Trade Fair News
25.03.2019 | Life Sciences
25.03.2019 | Information Technology