Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Mercury in Water, Fish Detected with Nanotechnology

Inexpensive, super-sensitive device detects even low levels of toxic metals in water, fish
When mercury is dumped into rivers and lakes, the toxic heavy metal can end up in the fish we eat and the water we drink. To help protect consumers from the diseases and conditions associated with mercury, researchers at Northwestern University in collaboration with colleagues at Ecole Polytechnique Fédérale de Lausanne (EPFL) in Switzerland, have developed a nanoparticle system that is sensitive enough to detect even the smallest levels of heavy metals in our water and fish.

The research was published September 9 in the journal Nature Materials.

“The system currently being used to test for mercury and its very toxic derivative, methyl mercury, is a time-intensive process that costs millions of dollars and can only detect quantities at already toxic levels,” said Bartosz Grzybowski, lead author of the study. “Ours can detect very small amounts, over million times smaller than the state-of-the-art current methods. This is important because if you drink polluted water with low levels of mercury every day, it could add up and possibly lead to diseases later on. With this system consumers would one day have the ability to test their home tap water for toxic metals.”

Grzybowski is the Kenneth Burgess Professor of Physical Chemistry and Chemical Systems Engineering in the Weinberg College of Arts and Sciences and the McCormick School of Engineering and Applied Science.

The new system is comprised of a commercial strip of glass covered with a film of “hairy” nanoparticles, a kind of a “nano-velcro,” that can be dipped into water. When a metal cation --- a positively charged entity, such as a methyl mercury --- gets in between two hairs, the hairs close up, trapping the pollutant and rendering the film electrically conductive.

A voltage-measuring device reveals the result; the more ions there are trapped in the “nano-velcro,” the more electricity it will conduct. To calculate the number of trapped particles, all one needs to do is measure the voltage across the nanostructure film. By varying the length of the nano-hairs covering the individual particles in the film, the scientists can target a particular kind of pollutant that is captured selectively. With longer “hairs,” the films trap methyl mercury, shorter ones are selective to cadmium. Other metals also can be selected with appropriate molecular modifications.

The nanoparticle films cost somewhere between $1 to $10 to make, and the device to measure the currents costs a few hundred dollars, Grzybowski said. The analysis can be done in the field so the results are immediately available.

Researchers were particularly interested in detecting mercury because its most common form, methyl mercury, accumulates as one goes up the food chain, reaching its highest levels in large predatory fish such as tuna and swordfish. In the United States, France and Canada, public health authorities advise pregnant women to limit fish consumption because mercury can compromise nervous system development in the fetus.

Researchers used this system to detect levels of mercury in water from Lake Michigan, near Chicago, among other samples. Despite the high level of industry in the region, the mercury levels were extremely low.

“The goal was to compare our measurements to FDA measurements done using conventional methods,” said Francesco Stellacci of EPFL, co-corresponding author of the study. “Our results fell within an acceptable range.”

The researchers also tested a mosquito fish from the Florida Everglades, which is not high on the food chain and thus does not accumulate high levels of mercury in its tissues. The U.S. Geological Survey reported near-identical results after analyzing the same sample.

"This technology provides an inexpensive and practical alternative to the existing cumbersome techniques that are being utilized today,” said Jiwon Kim, graduate student in Grzybowski’s lab in the department of chemistry at Northwestern. “I went to Lake Michigan with our sensor and a hand-held electrometer and took measurements on-site in less than a minute. This direct measurement technique is a dream come true for monitoring toxic substances."

This work was supported by the Non-equilibrium Energy Research Center, which is an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under grant number DE-SC0000989.

Authors of this study include: Jiwon Kim, Baudilio Tejerina, Thomas M. Hermans, Hideyuki Nakanishi, Alexander Z. Patashinski and Bartosz A. Grzybowski from the Department of Chemical and Biological Engineering and Department of Chemistry, Northwestern University; Eun Seon Cho and Francesco Stellacci, Institute of Materials, Ecole Polytechnique Fédérale de Lausanne EPFL Switzerland and Hao Jiang and Sharon C. Glotzer, Department of Chemical Engineering and Department of Materials Science and Engineering, University of Michigan.

Erin White is the broadcast editor. Contact her at

Erin White | EurekAlert!
Further information:

More articles from Ecology, The Environment and Conservation:

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

nachricht Malaysia's unique freshwater mussels in danger
27.09.2016 | The University of Nottingham Malaysia Campus

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: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

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

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>