Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Plugging in Molecular Wires

11.02.2009
It’s all in the wiring: biocomponents at the heart of an artificial photosystem

Plants, algae, and cyanobacteria (blue-green algae) are masters of everything to do with solar energy because they are able to almost completely transform captured sunlight into chemical energy.

This is in part because the electrons set free by the photons are transported out of the “light receptor” 1:1 to be used as the driving force for chemical reactions. Japanese researchers have now developed a new process to capture light energy with nearly equal efficiency.

As they report in the journal Angewandte Chemie, they “plug” a molecular “wire” directly into a biological photosynthetic system to efficiently conduct the free electrons to a gold electrode.

The efficiency of photovoltaic energy conversion is of critical significance for the practical application of solar installations. Theoretically, every photon absorbed should release one electron. Whereas modern solar cells are far from achieving high efficiency, natural photosynthetic systems achieve nearly 100 % quantum yield. To improve the efficiency of synthetic systems, experiments were attempted in which biological light-capturing units were deposited onto electrodes as thin films. However, the transfer of electrons from the light-capturing layer into the circuit in this type of system is so inefficient that most of the electrons don’t even make it to the target electrode.

The secret to the success of natural photosystems is the perfect fit of the individual components. The molecules fit precisely together like plugs and sockets and can pass electrons on directly and nearly without loss. The new approach taken by the Japanese researchers cleverly connects photosystem I (PSI) from the blue-green algae Thermosynechococcus elongatus with a synthetic apparatus. An important component of the electron transmission sequence of PSI is vitamin K1. The researchers removed the vitamin K1 from the PSI protein complex and replaced it with a synthetic analogue. This consists of three parts: 1) The same molecular “plug” with which vitamin K1 is bound to the protein complex (napthoquinone group) is used to “plug in” the synthetic binding component to PSI; 2) a molecular “wire” (hydrocarbon chain) with the same length as in vitamin K1 ensures that the binding component protrudes from the protein complex; and 3) at the other end of the wire is an additional “plug” (viologen group) that anchors the ensemble to a specially coated gold electrode. Electrons released by irradiation of PSI and transmitted along the wire are very efficiently transmitted to the gold electrode by the viologen group.

It may be possible to use this new strategy to integrate other biocomponents into synthetic systems.

Author: Nao Terasaki, National Institute of Advanced Industrial Science and Technology, Tosu (Japan), mailto:nao-terasaki@aist.go.jp

Title: Plugging a Molecular Wire into Photosystem I: Reconstitution of the Photoelectric Conversion System on a Gold Electrode

Angewandte Chemie International Edition 2009, 48, No. 9, 1585–1587, doi: 10.1002/anie.200805748

Nao Terasaki | Angewandte Chemie
Further information:
http://pressroom.angewandte.org

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>