University of Pittsburgh professor Kazunori Koide demonstrates the fluorescent marker that glows green in the presence of ozone. Dr. Koide led the team that developed the marker.
By David Templeton Pittsburgh Post-Gazette
A bright green glow definitely can draw attention.
So goes the thinking of Kazunori Koide who's developed a fluorescent solution dubbed "Pittsburgh Green" to detect rare but toxic metals including palladium, platinum and mercury.
Now the University of Pittsburgh associate professor of chemistry and his research team have created a similar fluorescent marker to detect even minute levels of ozone.
The latest research brightens Dr. Koide's earlier success by offering a potential means to signal ozone levels in the atmosphere that can cause respiratory problems in people with asthma. There's a direct correlation, he said, between ozone levels and emergency room visits.
Dr. Koide's fluorescent markers for palladium, platinum and mercury already are in various stages of development and use.
His ultimate goal is a separate fluorescent marker that signals the earliest gene expression of disease in the body. But that goal, Dr. Koide said, is "extremely ambitious and very competitive."
"It's been somewhat successful," he said. "We're on the right track, but it's not ready for prime time. Many other people are in the process of developing such a technology."
For now, his team, including researchers in Pitt's Graduate School of Public Health, have published a report in Nature Chemistry describing their simple, fast-acting detector that could be used in a consumer device, such as a badge, to measure surrounding ozone.
Another use could be a laboratory test to track ozone's role in the immune system.
"Dr. Koide is a terrific scientist -- A plus," said Dr. Bruce Pitt, chairman of the Department of Environmental and Occupational Health at Pitt's Graduate School of Public Health, who worked with the chemist on the ozone research. "He's great and he's cooking. He works fast, and he's goal-oriented."
He said Dr. Koide also is a rare chemist capable of working in the biomedical field.
Dr. Koide, a native of Kawagoe, Japan, and Pitt professor since 2000, began developing drugs that activate genes while a post-doctoral fellow at Harvard.
But the sole readily available detection method measured only the final protein levels, rather than specific steps of gene activity. With piqued interest, he began working with the common fluorescent, known as fluorescein, to try marking the steps in gene expression.
He said green fluorescence is stable and easy to store in the laboratory.
But soon he turned his attention to detecting rare metals and ozone with Pittsburgh Green -- an altered form of fluorescein he created that glows when excited by a blue laser.
The process offers a fast, simple way to indicate the presence of elements that otherwise are hard to detect.
Essentially he attaches a blocking molecule to fluorescein to prevent fluorescence. Only palladium, platinum, mercury or ozone remove the specific fluorescein blocker, depending on which element the solution is designed to detect. When that element is present, the blocker is removed and the fluorescein glows green under laser light.
A mining company has shown interest in using his marker to detect palladium and platinum. Dr. Koide also is developing a fluorescent system to detect platinum in the blood to prevent toxicity from drugs containing the metal.
While his fluorescent marker can detect mercury levels at 8 parts per billion in waste water, he's refining the process to glow when exposed to as little as 2 parts per billion -- the upper federal limit for mercury in drinking water in the United States.
Current tests for mercury, he said, require time and sophisticated equipment. "We can do this in the field because we don't need any fancy instruments," he said.
A Canadian research team is using his system to test for mercury in fish. Various parties have indicated interest in commercial and laboratory applications of his research.