Device speeds up tests for lead in water

A miniature device can measure trace levels of toxic lead in sediments at the bottom of harbors, rivers, and other waterways within minutes, researchers report.

That’s far faster than currently available laboratory-based tests, which take days.

“…someday you could go to a sushi bar and check whether the fish you ordered has lead or mercury in it.”

The affordable lab-on-a-chip device could also allow municipalities, water companies, universities, K-12 schools, daycares, and homeowners to easily and swiftly test their water supplies.

“In addition to detecting lead contamination in environmental samples or water in pipes in homes or elementary schools, with a tool like this, someday you could go to a sushi bar and check whether the fish you ordered has lead or mercury in it,” says senior author Mehdi Javanmard, an associate professor in the electrical and computer engineering department in the School of Engineering at Rutgers University–New Brunswick.

“Detecting toxic metals like lead, mercury, and copper normally requires collecting samples and sending them to a lab for costly analysis, with results returned in days,” Javanmard says.

“Our goal was to bypass this process and build a sensitive, inexpensive device that can easily be carried around and analyze samples on-site within minutes to rapidly identify hot spots of contamination.”

The research focused on analyzing lead in sediment samples. Many river sediments in New Jersey and nationwide are contaminated by industrial and other waste dumped decades ago. Proper management of contaminated dredged materials from navigational channels is important to limit potential impacts on wildlife, agriculture, plants, and food supplies.

Quick identification of contaminated areas could enable timely and cost-effective programs to manage dredged materials.

The new device extracts lead from a sediment sample and purifies it, with a thin film of graphene oxide as a lead detector. Graphene is an atom thick layer of graphite, the writing material in pencils.

More research is necessary to further validate the device’s performance and increase its durability so it can become a viable commercial product, possibly in two to four years.

Funding for the work came from Rutgers’ Center for Advanced Infrastructure and Transportation (CAIT).

Source: Rutgers University