Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Measuring mercury levels: Nano-velcro detects water-borne toxic metals

11.09.2012
A strip of glass covered in hairy nanoparticles can cheaply and conveniently measure mercury, which attacks the nervous system, and other toxic metals in fluids.
Researchers at the Swiss Federal Institute of Technology (EPFL), Northwestern University and the University of Michigan found that their new method can measure methyl mercury, the most common form of mercury pollution, at unprecedentedly small concentrations. The system, which could test for metal toxins in drinking water and fish, is reported in the current edition of Nature Materials.

Methyl mercury dumped in lakes and rivers accumulates in fish, reaching its highest levels in large, predatory fish such as tuna and swordfish. Young children and pregnant women are advised to avoid eating these fish because mercury can affect the developing brain and nervous system. While metals in drinking water are measured periodically, these measurements say little about migratory fish, including tuna, which may pass through more polluted areas.

"The problem is that current monitoring techniques are too expensive and complex," said researcher Francesco Stellacci, the Constellium Chair holder at EPFL. "With a conventional method, you have to send samples to the laboratory, and the analysis equipment costs several million dollars."

Using the device invented by the Swiss-American team, measuring the mercury levels in water or dissolved fish meat is as simple as dipping a strip of coated glass into the fluid. Metals and metallic molecules, such as methyl mercury, typically become positively charged ions in water. When these ions drift between the hairy nanoparticles, the hairs close up, trapping the pollutant. Passing a current over the strip of glass reveals how many ions are caught in the "nano-velcro." Each ion allows the strip to conduct more electricity.

U-M researchers Hao Jiang and Sharon Glotzer, the Churchill Professor of Chemical Engineering, performed computer simulations that investigated how the nano-velcro traps pollutants. They showed that the hairy nanoparticles are choosey about which ions they capture, confirming that the strips can give reliable measures of specific toxins as demonstrated by the experimental findings of the Swiss group.

"By making detection of pollutants and toxins cheap and easy to do, more testing at the source will lead to safer foods on the dinner table and in kids' lunchboxes," Glotzer said.

The scientists targeted particular pollutants by varying the length of the nano-hairs. This approach is especially successful for methyl mercury, and the device can measure it with record-breaking accuracy, detecting concentrations as low as 600 methyl mercury ions per cubic centimeter of water. Fortunately, that level of precision won't break the bank. The researchers estimate that the coated glass strips could cost less than 10 dollars each, while the measurement device will cost only a few hundred dollars. It could gauge the concentration of metals onsite and within minutes.

The researchers tested their method in Lake Michigan, near Chicago.

"The goal was to compare our measurements to FDA measurements done using conventional methods," Stellacci said.

Despite the industrial activity in the region, mercury levels were extremely low, in agreement with the FDA's analysis. The team also tested a mosquito fish from the Everglades.

"We measured tissue that had been dissolved in acid. The goal was to see if we could detect even very minuscule quantities," said Bartosz Grzybowski, the K. Burgess Professor of Physical Chemistry and Chemical Systems Engineering at Northwestern University, noting the species is too low on the food chain to accumulate high levels of mercury.

The United States Geological Survey reported near-identical results after analyzing the same sample.

"With this technology, it will be possible to conduct tests on a much larger scale in the field, or even in fish before they are put on the market," said researcher Hyewon Kim, MIT student visiting EPFL.

Funding for this research came from ENI, via the ENI-MIT Alliance; the U.S. Defense Threat Reduction Agency via a grant to MIT and U-M; and the U.S. Department of Energy via a Nonequilibrium Energy Research Center grant to Northwestern and the U-M.


Related Links:
Sharon Glotzer: http://che.engin.umich.edu/people/glotzer.html
Francesco Stellacci: http://people.epfl.ch/francesco.stellacci
Bartosz Grzybowski: http://dysa.northwestern.edu/bartosz.html

U-M Sustainability fosters a more sustainable world through collaborations across campus and beyond aimed at educating students, generating new knowledge, and minimizing our environmental footprint. Learn more at sustainability.umich.edu.

Nicole Casal Moore | EurekAlert!
Further information:
http://www.umich.edu

More articles from Ecology, The Environment and Conservation:

nachricht Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society

nachricht Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>