Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Materials governed by light

07.08.2017

Researchers at the UPV/EHU-University of the Basque Country have obtained hybrid photoactive materials with more stable and more rigid dyes that promise a broad range of applications

Hybrid materials are those that combine components of differing origins (organic and inorganic) in order to obtain materials different from conventional ones and which display new or improved properties owing to the synergistic effect between their components.


Channelled aluminophosphate with various encapsulated dyes emitting in the blue (acridine), green (pyronin Y) and red (LDS 722) regions of the spectrum, occluded separately (left) or simultaneously in the correct proportions to produce white light (right), under ultraviolet excitation light.

Credit: Rebeca Sola. UPV/EHU

Rebeca Sola, a researcher in the Department of Physical Chemistry in the UPV/EHU's Faculty of Science and Technology, has developed and exhaustively characterised hybrid, photoactive materials --which respond differently when exposed to excitation light-- which could have applications in highly different fields, such as optics and biomedicine.

In the research conducted in this department, hybrid materials were obtained, among other things, by incorporating fluorescent dyes, which are routinely used in solution, into channelled inorganic structures. These materials firstly give the dye protection, thus rendering it more stable against degradation and increasing the useful service life of the devices that incorporate them, and secondly, they provide the system with rigidity, which is interesting as this has the potential to increase the photophysical properties of the organic hosts (the dyes).

As the researcher explained, "highly fluorescent materials in which the dyes are found to be ordered were obtained, thus providing a highly anisotropic response to the linearly polarized light". In other words, materials that respond differently depending on the direction of the polarization of the incident light. Furthermore, it "is fairly straightforward," to synthesise these materials said Sola. "Crystalline structures in which the dye has already been occluded inside are obtained without any need to apply a diffusion process to insert the dye into the crystal."

Various optical applications

The researcher has thus obtained materials with a very wide range of optical properties. "Of great interest are those in which there is an artificial antenna effect with the ordering of the different kinds of dye and a unidirectional energy transfer," she said. This is translated into particles with multi-coloured fluorescence, which are capable of picking up the energy from light at one end and transferring it to the opposite end, which could be of interest with respect to integrating them into solar cells.

Another of the materials obtained is a solid material that emits delayed fluorescence: instead of the fluorescence of the system turning off as soon as the excitation source is removed, as is usually the case, it persists for tenths of a second and is perfectly visible to the naked eye. "This kind of technology could be of interest in LED technologies," she explained. And materials capable of transforming incident laser light into light with double the amount of energy were also obtained.

These materials not only allow the incorporation of a single dye into the inorganic structure, various dyes can also be simultaneously encapsulated. "With two dyes whose response is complementary, we have obtained fluorescent particles that change colour depending on the light polarization, and change from a blue fluorescent emission to a green one," added Sola. What is more, it is a reversible, reproducible process". By incorporating a third, red-emission dye in the correct proportion, a white-light emitting system was also obtained, "once again of interest for illumination systems," she concluded.

White-light emitters were also obtained by adding small organic molecules to certain frameworks of metal ions and organic compounds known as MOFs (Metal Organic Frameworks); ambient-temperature phosphorescence was also obtained with them. "Phosphorescence is an emission process that routinely calls for very low temperatures to prevent the phosphorescent light from deactivating," explained Sola.

Leap to biomedicine

The researchers have shown that hybrid materials may have applications in other fields, such as biomedicine. To do this, they used photosensitising substances suitable for photodynamic therapy. These are materials that combine organic and inorganic fragments to produce a kind of oxygen capable of causing the death of certain cells following excitation by light. Photodynamic therapy is a procedure used in dermatology, for example, to treat a range of skin diseases and even for different types of cancer. Materials that not only generate this type of cytotoxic oxygen but which are also fluorescent have been obtained. And "that makes them very useful for bioimaging as well," added the researcher. "The phototoxic action of these compounds is being explored by means of experiments in in-vitro cell cultures, and although the results are promising, we are still in the early phases of the study," she concluded.

###

Additional information

This study is part of the PhD thesis by Rebeca Sola-Llano (Barakaldo, 1989), entitled 'Synergism between organic and inorganic moieties: in the search of new hybrid materials for optics and biomedicine'. Her supervisors were the Ramón y Cajal researcher Virginia Martínez-Martínez and the UPV/EHU professor Iñigo López-Arbeloa. Research groups at the Institute of Catalysis and Petrochemistry in Madrid, the Complutense University of Madrid, the University of Kyoto, the Katholieke Universiteit of Leuven and the Autonomous University of Madrid collaborated in this thesis.

Bibliographical reference

M. J. Ortiz, E. Palao, R. Sola-Llano, A. Tabero, H. Manzano, A. R Agarrabeitia, A. Villanueva, I. López-Arbeloa, V. Martinez-Martinez. 'AcetylacetonateBODIPY?biscyclometalated Iridium(III) complexes: Effective strategy towards smarter fluorescent-photosensitizer agents' (2017). Chem. Eur. J. 10.1002/chem.201701347

Media Contact

Matxalen Sotillo
komunikazioa@ehu.eus
34-688-673-770

 @upvehu

http://www.ehu.es 

Matxalen Sotillo | EurekAlert!

Further reports about: biomedicine fluorescence fluorescent hybrid materials inorganic optics polarization

More articles from Materials Sciences:

nachricht Borophene shines alone as 2-D plasmonic material
21.11.2017 | Rice University

nachricht Quantum dots amplify light with electrical pumping
21.11.2017 | DOE/Los Alamos National Laboratory

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

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,...

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

Previous evidence of water on mars now identified as grainflows

21.11.2017 | Physics and Astronomy

NASA's James Webb Space Telescope completes final cryogenic testing

21.11.2017 | Physics and Astronomy

New catalyst controls activation of a carbon-hydrogen bond

21.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>