Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tokyo Institute of Technology researchers develop blue-fluorescent molecular nanocapsules by ...

13.07.2012
... simple mixing ‘green-environmentally friendly’ metal ions and bent organic blocks.

The fluorescent molecular nanocapsules have potential applications as sensors, displays, and drug delivery systems (DDS).

Michito Yoshizawa, Zhiou Li, and collaborators at Tokyo Institute of Technology (Tokyo Tech) synthesized ~1 nanometer-sized molecular capsules with an isolated cavity using green and inexpensive zinc and copper ions. In sharp contrast to previous molecular capsules and cages composed of precious metal ions such as palladium and platinum, these nanocapsules emit blue fluorescence with 80% efficiency.

Molecular nanocapsules have potential applications as photo-functional compounds and materials but so far molecular capsules synthesized by incorporating palladium ions and so on exhibit poor fluorescence.

The Tokyo Tech researchers expect to be able to prepare multicolor fluorescence composites by the simple insertion of appropriate fluorescent molecules into the isolated cavity of the nanocapsules.

DETAILS:

Fluorescence has widespread applications, helping researchers to understand issues in the fundamental sciences and develop practical materials and devices. Among the useful fluorescent compounds in development, capsule-shaped molecular architectures, which possess both strong fluorescent properties and a nanometer-sized cavity, are particularly promising.

Molecular cages and capsules can be prepared through a simple synthetic process called coordinative self-assembly. However, most of them are composed of precious metal ions such as palladium and platinum, and are non-emissive due to quenching by the heavy metals.

Now, Michito Yoshizawa, Zhiou Li, and co-workers from the Chemical Resources Laboratory at Tokyo Institute of Technology report novel molecular nanocapsules with the M2L4 composition (where M represents zinc, copper, platinum, palladium, nickel, cobalt, and manganese). Their zinc and copper capsules, in particular, display unique fluorescent properties.

The M2L4 capsules self-assemble from two metal ions and four bent ligands that include anthracene fluorophores (fluorescent parts). X-ray crystallographic analysis verified the closed shell structures where the large interior cavities of the capsules, around one nanometer in diameter, are shielded by eight anthracene panels.

The zinc capsule emitted strong blue fluorescence with a high quantum yield (80%), in sharp contrast to the weakly emissive nickel and manganese capsules and the non-emissive palladium, platinum, and cobalt capsules. The fluorescence of the copper capsule, on the other hand, depends on the solvent; for example, it shows blue emission in dimethyl sulfoxide but no emission in acetonitrile.

This study is the first to show such emissive properties of molecular capsules bearing an isolated large cavity. The researchers believe their nanocapsules could have novel applications in devices such as chemosensors, biological probes, and light-emitting diodes.

Reference:

Zhiou Li, Norifumi Kishi, Kenji Yoza, Munetaka Akita, Michito Yoshizawa, “Isostructural M2L4 Molecular Capsules with Anthracene Shells: Synthesis, Crystal Structures, and Fluorescent Properties”, Chemistry - A European Journal, 18, 8358 (2012). DOI: 10.1002/chem.201200155.


Further information:

Center for Public Information
Tokyo Institute of Technology
2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
E-mail: kouhou@jim.titech.ac.jp
Tel: +81-3-5734-2975
Fax: +81-3-5734-3661


About Tokyo Institute of Technology

As one of Japan’s top universities, Tokyo Institute of Technology seeks to contribute to civilization, peace and prosperity in the world, and aims at developing global human capabilities par excellence through pioneering research and education in science and technology, including industrial and social management. To achieve this mission, we have an eye on educating highly moral students to acquire not only scientific expertise but also expertise in the liberal arts, and a balanced knowledge of the social sciences and humanities, all while researching deeply from basics to practice with academic mastery. Through these activities, we wish to contribute to global sustainability of the natural world and the support of human life.

Adarsh Sandhu | Research asia research news
Further information:
http://www.titech.ac.jp/english/
http://www.researchsea.com/html/article.php/aid/7329/cid/2?

More articles from Life Sciences:

nachricht New photocatalyst speeds up the conversion of carbon dioxide into chemical resources
29.05.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)

nachricht Copper hydroxide nanoparticles provide protection against toxic oxygen radicals in cigarette smoke
29.05.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Strathclyde-led research develops world's highest gain high-power laser amplifier

The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.

The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

New photocatalyst speeds up the conversion of carbon dioxide into chemical resources

29.05.2017 | Life Sciences

NASA's SDO sees partial eclipse in space

29.05.2017 | Physics and Astronomy

New drug reduces transplant and mortality rates significantly in patients with hepatitis C

29.05.2017 | Statistics

VideoLinks
B2B-VideoLinks
More VideoLinks >>>