The laboratory study, which involved pumpkin plants, indicates a possible pathway for nanoparticles to enter the food chain. The research also reveals a new experimental approach for studying nanoparticles and their potential impacts.
Yan Jin, professor of soil physics in the University of Delaware College of Agriculture and Natural Resources, and John Xiao, professor of physics and astronomy in the College of Arts and Sciences, led the study, working with colleagues Jung-youn Lee and Harsh Bais at the Delaware Biotechnology Institute, a premier research center at the University of Delaware.
The results were published in a cover article in the Journal of Environmental Monitoring and also were highlighted in Chemical Biology, a journal of the Royal Society of Chemistry.
Nanoparticles are bits of chemicals a thousand times smaller than a human cell. While nanoparticles occur naturally in the environment, they increasingly are being manufactured for use in electronics to cosmetics, fuel cells to medical procedures.
Yet the human and environmental health risks associated with these tiny engineered particles are not well known. Because chemical compounds can take on different properties at such a reduced size--lead in a pencil reportedly becomes stronger than steel, for example--there is concern that these invisible particles could easily be breathed in by humans and animals, with damaging or toxic effects.
“Plants serve as a foundation of the food chain,” noted Jin, who was recently named a fellow of the Soil Society of America. “We demonstrated this possible route for nanoparticles in the environment--whether it poses potential harm to human health depends on many factors. This is a preliminary study, which we hope will spur additional interdisciplinary research by the scientific community.”
The researchers chose pumpkins for the study, Jin said, because they take in a lot of water and are easy to grow.
The plants were grown hydroponically in an aqueous medium to which nanoparticles of iron oxide, or magnetite, a magnetic form of iron ore, were added.
After 20 days of growth, the plants were cut into pieces and dried in a vacuum dessicator. A magnetometer was then used to detect if any of the particles had been absorbed by the plant.
“Our study was a worst-case scenario in order to test the feasibility of our approach in being able to detect the particle,” Xiao noted. “It really provides a new technique for doing this kind of research.”
Xiao, who directs the Center for Spintronics and Biodetection at the University of Delaware, noted that the magnetometer used in his physics research is similar to magnetic resonance imaging (MRI), which uses a powerful magnetic field and radio-frequency pulses to produce images of internal structures in the human body.
The magnetometer subjected the dried pumpkin plants to a low-frequency monotone to vibrate them. The vibration revealed each tiny particle of magnetite's unique magnetic signal and, thus, exact location inside the plant.
The researchers noted that in their initial screening tests, no magnetic signals were detected in lima bean plants compared to the strong signals in pumpkin plants, which suggests that different plants have varied responses to nanosized particles.
Additionally, while the pumpkins were studied primarily in aqueous media, the researchers also tested the plants in sand to which nanoparticles were added, where there was little uptake, and in soil, where there was no uptake of nanoparticles at all, according to Jin.
Jin noted how important interdisciplinary collaboration has been to the research and said she hopes to see plant scientists and molecular biologists involved in future studies to see how nanoparticles actually get into plants.
“Some believe it is a passive process; others are convinced it is an active one,” Jin said. “There could be whole other lines of research,” she noted.
“It's like a saying we have in Chinese,” Jin added. “You throw out a brick and hope to attract a jade.”
The saying, which is a Chinese way of showing humility, demonstrates the speaker's hope that others will improve on an idea.
“We want to stress that our study is very preliminary, and we hope it will stimulate more research in this area,” she said.
The project was funded by the Delaware Experimental Program to Stimulate Competitive Research (EPSCoR), which is supported by the National Science Foundation and the state of Delaware.
Jin and Xiao also recently won a STAR grant from the Environmental Protection Agency to examine the fate and transport of engineered nanoparticles in porous media, including soil and groundwater.
See the complete story and photos at this University of Delaware Web site: http://www.udel.edu/udaily/2009/nov/pumkpkins111108.html
University of Delaware | Newswise Science News
At last, butterflies get a bigger, better evolutionary tree
16.02.2018 | Florida Museum of Natural History
New treatment strategies for chronic kidney disease from the animal kingdom
16.02.2018 | Veterinärmedizinische Universität Wien
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).
Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
16.02.2018 | Information Technology
16.02.2018 | Health and Medicine
16.02.2018 | Physics and Astronomy