Nanotech is Making Water Testing Quicker & Easier

This cartridge uses special nanotechnology to detect trace amounts of chemical contaminants in water. CREDIT: Mark C. Peterman, OndaVia, Inc. View full size image

This Research in Action article was provided to LiveScience in partnership with the National Science Foundation.

New, technologically advanced cartridges made by OndaVia, Inc, are able to test water for trace-level contaminants quicker and easier than traditional methods, meaning safer water for all.

Detection of low-level contaminants in water generally involves expensive, complex laboratory instruments to separate out chemicals and detect them at very low levels. For example, some contaminants are dangerous at parts per billion, which is equal to one drop in fifty drums of liquid.

The detection of those low-level, trace contaminants also can require shipping samples to a laboratory and potentially weeks of time before results are available. Meanwhile, the public is exposed to potentially contaminated water while awaiting the results.

By combining two fields of research, OndaVia found a way to measure trace contaminants in a fraction of the time, expense and complexity currently required. OndaVia's cartridge detectors use channels — smaller than a human hair — etched in silicon to separate chemicals. This science of manipulating fluids at the micro-scale, called microfluidics, has been widely applied to chemical separations, most notably to analyze genes.

In OndaVia's novel approach, the etched channel is not of a uniform width; its width varies, causing molecules of different sizes to move at different speeds, in which spreads out the difference sized molecules in the water sample.

The output of the separation channel is funneled to a cluster of tiny gold pieces called nanoparticles. Nanoparticles, objects with features less than 100 nanometers in size (about the size of a viral particle).

These tiny particles offer a variety of surprising properties, with applications from electronics to medicine. In the OndaVia cartridge, the gold nanoparticles — each 40 nm in diameter (the size of an HIV particle) — interact with light to amplify the signal from passing contaminants. Measurement of the amplified signal makes trace detection and chemical identification possible.

The OndaVia team has shown trace-level detection of benzene, a cancer causing component in oil, in Gulf Coast beach water; the've found the toxic compound melamine, the same compound used to trick protein-level tests during the 2008 Chinese milk scandal, in infant formula; and they've found perchlorate, a chemical that disrupts hormone production, in California ground water.

Through National Science Foundation Small Business Innovation Research grants, the OndaVia team is transitioning the technology into a single-use consumable cartridge for rapid, field-based water analysis.

The researchers will demonstrate a cartridge for perchlorate analysis at the Spring 2012 American Chemical Society National Meeting & Exposition in San Diego, California and will present results of this work at the AIChE Spring meeting April 3, 2012, in Houston, Texas.

Editor's Note: Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science Foundation. See the Research in Action archive.