University of Oregon chemists have developed a selective probe that detects hydrogen sulfide (H2S) levels as low as 190 nanomolar (10 parts per billion) in biological samples. They say the technique could serve as a new tool for basic biological research and as an enhanced detection system for H2S in suspected bacterially contaminated water sources.
Hydrogen sulfide, a colorless gas, has long been known for its dangerous toxicity -- and its telltale smell of rotten eggs -- in the environment, but in the last decade the gas has been found to be produced in mammals, including humans, with seemingly important roles in molecular signaling and cardiac health. Detection methods for biological systems are emerging from many laboratories as scientists seek to understand the roles of H2S in general health and different diseases.
Reporting in the Journal of Organic Chemistry -- online in advance of regular print publication -- researchers in the UO lab of Michael D. Pluth, professor of chemistry, describe the development of a colorimetric probe that relies on nucleophilic aromatic substitution to react selectively with H2S to produce a characteristic purple product, allowing for precise H2S measurement.
"This paper describes a new way to selectively detect H2S," said Pluth, who has been pursuing detection methods for the gas under a National Institutes of Health "Pathway to Independence" grant. That early career award began while he was a postdoctoral researcher at the Massachusetts Institute of Technology. "This technique allows you to use instruments to quantify how much H2S has been produced in a sample, and the distinctive color change allows for naked-eye detection."
In biological samples, he said, the approach allows for a precise measurement. In the environment, he added, the technique could be used to determine if potentially harmful H2S-producing bacteria are a contaminant in water sources through the creation of testing kits to detect the gas when levels are above a defined threshold.
The key to the technique, said the paper's lead author, doctoral student Leticia A. Montoya, is the reaction process in which the probe reacts with H2S to produce a distinctly identifiable purple compound. "This method allows you look selectively at hydrogen sulfide versus any other nucleophiles or biological thiols in a system," Montoya said. "It allows you to more easily visualize where H2S is present."
The chemical reaction produced in the experiments, Pluth said, also holds the potential to be applied in a variety of materials, on surfaces and films, with appropriate modifications. The UO has applied for a provisional patent to cover the technology.
The study is the second in which Pluth's lab has reported potential detection probes for H2S. Last year, in the journal Chemical Communications, Montoya and Pluth described their development of two bright fluorescent probes that sort out H2S from among cysteine, glutathione and other reactive sulfur, nitrogen and oxygen species in living cells.
"We're really interested in making sharper tools," Pluth said. "We have the basic science worked out, and now we want to move forward to fine-tune our tools so that we can better use them to answer important scientific questions."
"University of Oregon researchers are helping to foster a more sustainable future by developing powerful new tools and entrepreneurial technologies," said Kimberly Andrews Espy, vice president for research and innovation and dean of the UO graduate school. "This important research from Dr. Pluth's lab may someday alert us to environmental contaminants and could also impact basic science and human health."
Co-authors with Montoya and Pluth on the newly published paper were UO undergraduate students Taylor F. Pearce and Ryan J. Hansen, and Lev N. Zakharov of the UO-based Center for Advanced Materials Characterization in Oregon (CAMCOR). The NIH grant to Pluth (R00 GM092970) came from the National Institute for General Medical Sciences. The research also utilized UO-based nuclear magnetic resonance facilities that are supported by the National Science Foundation (ARRA CHE-0923589).
About the University of Oregon
The University of Oregon is among the 108 institutions chosen from 4,633 U.S. universities for top-tier designation of "Very High Research Activity" in the 2010 Carnegie Classification of Institutions of Higher Education. The UO also is one of two Pacific Northwest members of the Association of American Universities.
Sources:Michael D. Pluth
Jim Barlow | EurekAlert!
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences