Used in the proper amounts, it can make teeth stronger and aid in the treatment of osteoporosis. When excessive amounts are consumed, however, it can be a killer a carcinogen that causes bone, lung and bladder cancers. The "it" is fluoride, a common additive in most American communities' drinking water and an ingredient in the vast majority of commercially produced adult toothpastes.
Determining the level of fluoride, be it in water, consumer products or the human body, is an important and attractive challenge for scientists. To address that, a Florida State University researcher has developed a molecular sensor that changes color when a sample containing fluoride is added to it.
"The U.S. Environmental Protection Agency recommends that 1 part per million (ppm) of fluoride ions is acceptable in drinking water, but above 2 ppm is considered a serious health risk," said Sourav Saha, an assistant professor in FSU's Department of Chemistry and Biochemistry (http://www.chem.fsu.edu/) and its Integrative NanoScience Institute (http://insi.fsu.edu/). "Because fluoride is carcinogenic even at such small doses, a sensor is needed to detect fluoride selectively at very low concentrations and in the presence of other naturally occurring and biologically important ions."
Working with a team of graduate students and postdoctoral researchers, Saha was able to develop just such a sensor. His research team discovered that a compound called naphthalene diimide (NDI) interacts with fluoride ions in a uniquely colorful way.
"NDIs are a family of neutral (albeit electron-deficient) aromatic compounds that are colorless until fluoride is added," Saha said. "A small amount of fluoride will quickly turn the sample orange, while a larger amount will turn it pink. In this manner, it becomes very easy to determine not only the presence of fluoride in water, but at what leve
|Contact: Sourav Saha|
Florida State University