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Described in the article is the development of a low-cost,disposable lab-on-a-chip sensor that detects highly electronegativeheavy metals more quickly than current technology generallyavailable in health-care settings. It's envisioned that the new UCsensor technology will be used in point-of-care devices thatprovide needed feedback on heavy-metal levels within about tenminutes. It's expected that the sensor will have potential for large-scaleuse in clinical, occupational and research settings, e.g., for nutrition testing in children. The new sensor is environmentally friendly in that its workingelectrode is made of bismuth vs. the more typical mercury, and it'schild friendly in that it requires only a droplet or two of bloodfor testing vs. the typical five-milliliter sample now required. Explained one of the researchers, UC's Ian Papautsky, "Theconventional methods for measuring manganese levels in bloodcurrently requires about five milliliters of whole blood sent to alab, with results back in 48 hours. For a clinician monitoringhealth effects by measuring these levels in a patient's blood -where a small level of manganese is normal and necessary formetabolic functions - you want an answer much more quickly aboutexposure levels, especially in a rural, high-risk area where accessto a certified metals lab is limited. Our sensor will only requireabout two droplets of blood serum and will provide results in aboutten minutes. It's portable and usable anywhere." Papautsky, UC associate professor of electrical and computerengineering, is co-author of the Biomedical Devices-publishedresearch, "Lab-on-a-Chip Sensor for Detection of HighlyElectronegative Heavy Metals by Anodic Stripping Voltammetry."Other co-authors are Erin Haynes, assistant professor ofenvironmental engineering; William Heineman, distinguished researchprofessor of chemistry; and just-graduated electrical and computerengineering doctoral student Preetha Jothimuthu, just-graduatedchemistry doctoral student Robert Wilson, and biomedicalengineering undergraduate research co-op student Josi Herren. FIRST FIELD TEST OF SENSOR EXPECTED IN 2012 IN MARIETTA, OHIO One specific motivation for developing the sensor was an ongoingproject by UC's Erin Haynes, who is studying air pollution and thehealth effects of manganese and lead in Marietta, Ohio. Manganeseis emitted in that area because it is home to the only manganeserefinery in the United States and Canada. Preliminary results fromUC's Mid-Ohio Valley Air Pollution Study (M.A.P.S.) found elevatedlevels of manganese in Marietta residents when compared to thosewho live in other cities. HOW THE UC SENSOR WORKS The new UC sensor uses a technology called anodic strippingvoltammetry that incorporates three electrodes: a workingelectrode, a reference electrode and an auxiliary electrode. A critical challenge for such sensors is the detection ofelectronegative metals like manganese. Detection is difficultbecause hydrolysis, the splitting of a molecule into two parts bythe addition of a water molecule, at the auxiliary electrodeseverely limits a sensor's ability to detect an electronegativemetal. To resolve this challenge, the UC team developed a thin-filmbismuth working electrode vs. the conventional mercury or carbonelectrode. The favorable performance of the bismuth workingelectrode combined with its environmentally friendly nature meansthe new sensor will be especially attractive in settings where adisposable lab-on-a-chip is wanted. In addition, the UC team also optimized the sensor layout andworking-electrode surface to further reduce the effects ofhydrolysis and to boost the reliability and sensitivity indetecting heavy metals. The new sensor layout better allowed forits functioning, which consists of taking of a blood serum sample,stripping out the heavy metal and then measuring that heavy metal. The end result is the first lab-on-a-chip able to consistentlypinpoint levels of highly electronegative manganese in humans. Thenew sensor also exhibits high reliability over multiple days ofuse, with hours of continuous operation. With further developments,the chip may even be converted into a self-check mechanism, such aswith glucose screening for diabetics. FUNDING Funding for this research has been provided by the NationalInstitute of Environmental Health Sciences, the National Instituteof Occupational Safety and Health Pilot Research Project TrainingProgram and the University of Cincinnati. Additional References Citations. I am an expert from infraredinteractivewhiteboard.com, while we provides the quality product, such as China Interactive Voting Handsets , RF Wireless Tablet, Infrared Interactive Whiteboard,and more.
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