Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A Good Eye for Oxygen

27.03.2009
Dye-doped nanoparticles very precisely indicate the oxygen concentration of cells and tissues

We cannot live without it; yet too much of it causes damage: oxygen is a critical component of many physiological and pathological processes in living cells.

Oxygen deficiency in tissues is thus related to tumor growth, retinal damage from diabetes, and rheumatoid arthritis. It is thus important to determine the oxygen content of cells and tissues, which is a challenge to scientists.

A team led by Jason McNeill at Clemson University (USA) has now developed a new technique based on dye-doped nanoparticles. As reported in the journal Angewandte Chemie, they are able to carry out very sensitive quantitative oxygen determinations.

Nanoparticle-based oxygen sensors typically consist of phosphorescent dyes encapsulated by a polymer or silica gel particle to shield the dye from the cellular environment. The nanoparticles also intensify the radiation of the dye. The American researchers have now developed a new nanoparticle architecture: they used a polymer with a special ð-conjugated electronic structure. The electrons can thus move more-or-less freely over the entire molecule.

The researchers used this polymer to produce nanoparticles that they doped with a platinum-porphyrin complex, an oxygen-sensitive phosphorescent dye. When irradiated, the polymer very efficiently absorbs the light energy and passes it on to the dye in “energy packets”. This results in phosphorescence that is five to ten times brighter than previous nanoparticle-based oxygen sensors. In comparison to conventional oxygen sensors, the light emitted is 1000 times brighter.

The particles are highly sensitive to oxygen: in nitrogen-saturated solution, the sensors initially glow intensely red. When oxygen is introduced, the dye interacts with it, reducing the phosphorescence. The more oxygen is present, the more the phosphorescence is quenched. The researchers were thus not only able to determine the concentration-dependence of the brightness, but also the lifetime of the phosphorescence: the duration of the dye’s glow is dependent on the oxygen concentration.

The new sensor is sensitive enough to detect individual particles. Because the nanoparticles are easily taken up by cells, they are ideal for the quantitative description of the local oxygen concentrations in living cells and tissues.

Author: Jason McNeill, Clemson University (USA), http://chemistry.clemson.edu/people/mcneill.html#1

Title: Ratiometric Single-Nanoparticle Oxygen Sensors for Biological Imaging

Angewandte Chemie International Edition 2009, 48, No. 15, 2741–2745, doi: 10.1002/anie.200805894

Jason McNeill | Angewandte Chemie
Further information:
http://pressroom.angewandte.org
http://chemistry.clemson.edu/people/mcneill.html#1

More articles from Life Sciences:

nachricht Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>