Researchers at the University of Cincinnati have created a disposable lab-on-a-chip sensor that can test levels of potentially harmful heavy metals in humans in as few as 10 minutes.
Their work, published in the August issue of the journal Biomedical Microdevices, is co-authored by assistant professor of environmental engineering Erin Haynes, who has also been studying air pollution and the effects of lead and manganese on residents in Marietta, Ohio--home to the only manganese refinery in the U.S. and Canada. (Manganese compounds are used to make steel and other products.)
Manganese is naturally ubiquitous and considered essential both nutritionally and physiologically to humans, according to the Environmental Protection Agency. Chronic exposure via inhalation, however, can cause manganism, a syndrome that can lead to difficulty walking, tremors, speech disturbances, impotence, and psychological issues.
Unlike current manganese and heavy metal tests, the University of Cincinnati sensor requires only a couple drops of blood (instead of 5 milliliters) and takes just 10 minutes (instead of two days) to deliver results. And because its working electrode is made of bismuth instead of mercury, the researchers say it's more environmentally friendly.
"For a clinician monitoring health effects by measuring these levels in a patient's blood--where a small level of manganese is normal and necessary for metabolic functions--you want an answer much more quickly about exposure levels, especially in a rural, high-risk area where access to a certified metals lab is limited," says Ian Papautsky, one of the researchers.
The new sensor works by stripping the heavy metal from the blood serum sample and then measuring it. In testing, it has consistently pinpointed manganese levels and is highly accurate over several days of use, making it potentially useful for self-monitoring.
The team says the sensor has the potential to be used in large-scale clinical, research, and occupational settings, including for nutrition testing in children.