Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researcher develops accurate method for detecting dangerous fluoride

10.12.2010
Sourav Saha's molecular sensor could protect people from a potential carcinogen

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 levels."

While other fluoride sensors exist, many of them cannot differentiate between fluoride and other anions — negatively charged ions — that might be present in the water.

"Although they can detect fluoride, they cannot accurately measure the levels of fluoride," Saha said. "Naked-eye detection of fluoride at different concentration levels is an advantage of NDI-based sensors. Our sensor relies on an electron transfer event from a fluoride ion to the NDI receptor for generating a visible response or signal, which in this case is color change. The electron transfer process can be reversed, and the sensor can be regenerated and reused over and over again."

By designing an appropriate sensor, Saha's laboratory has achieved a remarkable "nanomolar" sensitivity for fluoride, meaning it can detect about one ten-thousandth of a milligram of fluoride in a liter of water. This makes it one of the most sensitive fluoride sensors known to date.

Water fluoridation has been widely used in the United States since about 1960. Although often a subject of controversy, Saha says it has had the effect of improving overall dental health through a very basic chemical process. When added to water systems, fluoride reacts with a naturally occurring mineral, calcium phosphate, and produces a compound called fluorapatite. Fluorapatite then bonds with humans' teeth to form a hard, protective layer that wards off corrosion. This is important for dental health.

However, excessive amounts of fluoride in water can cause a condition known as dental fluorosis, especially in young children. This results in a mottled appearance of the dental enamel, as well as possible cracking and pitting of the teeth.

Fluoride is also used in several drugs prescribed to treat the brittle-bone disease osteoporosis. Given in the proper amounts, the fluoride appears to stimulate the formation of new bone tissue. However, when excessive amounts of fluoride build up in body tissues, they can lead to a variety of health maladies, including skeletal fluorosis, which causes pain and damage to bones and joints. Excessive fluoride over a length of time has also been linked to the development of osteosarcoma — a malignant and potentially fatal bone cancer — as well as cancers of the lungs and bladder. For those reasons and others, fluoride has not been formally approved by the Food and Drug Administration for the treatment of osteoporosis in the United States.

Artificial fluoridation of drinking water is commonly practiced in many industrialized nations. While precise numbers are unavailable, perhaps 400 million people living outside of the United States are located in areas where water is artificially fluoridated, according to the British Fluoridation Society. Untold millions of others, especially in parts of Africa, India and China, rely on water sources whose natural fluoride levels exceed EPA recommendations. Efforts to measure the amount of fluoride present in many of those areas are inconsistent and imprecise.

"This is a very significant public health issue worldwide," Saha said. "Some developing countries fluoridate their water but don't have a means for measuring it accurately. Others are drinking water that hasn't been treated with fluoride but that might already contain dangerous amounts naturally. Clearly there is a critical need for a fluoride sensor that can tell people whether their water supply is safe."

A paper describing his team's findings was recently published by the Journal of the American Chemical Society. "Fluoride Ion Sensing by an Anion-n Interaction" (http://pubs.acs.org/doi/abs/10.1021/ja107382x) was coauthored by Saha and his postdoctoral researcher, Samit Guha. It was also highlighted in the Dec. 6, 2010, issue of Chemical and Engineering News (http://pubs.acs.org/cen/).

In addition, Saha filed for a U.S. patent on his fluoride-sensing process in June 2010; he hopes to know within the next year whether the patent will be granted. If it is, the next step likely would be to license his discovery to an outside company that could test it for commercial potential and then, if all goes well, develop it into a marketable product.

"This is a clever idea," said John Fraser, Florida State's assistant vice president for Research and Economic Development and director of the Office of Intellectual Property Development and Commercialization (http://www.research.fsu.edu/techtransfer/). "Using a simple color test to determine safe fluoride levels will lead to a tangible benefit to society. Once commercialized, people will benefit in the United States, but also in countries with high natural but unsafe levels of fluoride."

Sourav Saha | EurekAlert!
Further information:
http://www.fsu.edu

More articles from Life Sciences:

nachricht Tag it EASI – a new method for accurate protein analysis
20.06.2018 | Max-Planck-Institut für Biochemie

nachricht How to track and trace a protein: Nanosensors monitor intracellular deliveries
19.06.2018 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Creating a new composite fuel for new-generation fast reactors

20.06.2018 | Materials Sciences

Game-changing finding pushes 3D-printing to the molecular limit

20.06.2018 | Materials Sciences

Could this material enable autonomous vehicles to come to market sooner?

20.06.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>