When fungi, such as penicillium, grow, they form a thread-like network, the mycelium. If the fungus is grown in a medium containing nanoscopic particles of a noble metal, the resulting mycelium is coated with the nanoparticles.
As researchers from the Technical University in Dresden and the Max Planck Institute for the Chemical Physics of Solid Materials in Dresden (Germany) report in the journal Angewandte Chemie, such hybrids could be an interesting new approach for the production of catalytic systems.
The team, led by Alexander Eychmüller and Karl-Heinz Pée, cultivated various types of fungus in media with finely divided (colloidal) nanoparticles of noble metals. In the presence of the tiny gold, platinum, or palladium particles, the fungi grew with no appreciable impairment. Silver particles, which are toxic to microorganisms, were also tolerated by one variety of fungus. The nanoparticles are deposited on the surface of the growing mycelium—without any special modification beforehand. Thus hybrid systems made of fungi and noble metals are formed: tubular hyphae covered in multiple layers of individual nanoparticles.
The optical properties of nanoscopic particles depend on their size. The researchers determined that the optical properties of their deposited particles differ only slightly from those of the nanoparticles in solution. Fungal threads with a 0.2µm gold covering thus appear reddish brown, like a solution of such gold nanoparticles. This is evidence that the nanoparticles have not aggregated to form larger units.
Because the particles remain separate, the mycelium-bound noble metal nanoparticles should also retain their special catalytic activities. The researchers were thus able to determine that a platinum–fungus hybrid catalyzes the redox reaction of hexacyanoferrate and thiosulfate in aqueous solution. The “enobled” fungal mycelium offers a system easy to separate from the solution after the reaction and a highly specific surface—important for a catalyst.
Author: Alexander Eychmüller, Technische Universität Dresden (Germany), http://www.chm.tu-dresden.de/pc2/AlexLebenslaufWeb.shtml
Title: Fungal Templates for Noble-Metal Nanoparticles and Their Application in Catalysis
Angewandte Chemie International Edition 2008, 47, No. 41, 7876–7879, doi: 10.1002/anie.200801802
Alexander Eychmüller | Angewandte Chemie
The birth of a new protein
20.10.2017 | University of Arizona
Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research