The Alchemist Newsletter: Nov 30, 2012

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A polymer and protein hybrid membrane can trap nanoparticles in aqueous solution and act as a solar absorber. Mady Elbahri and his team from the Institute of Material Science at Kiel University (KU) and the Institute of Polymer Research at Helmholtz-Zentrum Geesthacht (HZG), Germany, published details in the journal Advanced Functional Materials. They explain that conformational changes in the protein can sequester nanoparticles from solution but surprisingly the color of the nanoparticles shines through. Gold nanoparticles trapped are red when the material is dry but a perfect black absorber when wet. “All in all, the result is a breakthrough towards the design of an operative filtration process, as a new route for the fabrication of functional materials, and offers commercially attractive efficiencies at a low cost”, explains Elbahri.

Sieve holds nanoparticles and acts as solar absorber

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Combining scanning transmission electron microscopy and atomic-resolution spectroscopic techniques has allowed researchers at Oak Ridge National Laboratory, in Oak Ridge and at Vanderbilt University, Nashville, Tennessee, to probe individual silicon impurities in a sheet of the carbon-based material graphene. Graphene has been mooted as an important component of future microelectronic and optoelectronic devices with the potential to bridge the gap between conventional silicon semiconductor circuitry and a future generation of molecular devices. The presence of silicon atoms can affect graphene's properties and so understanding the behavior of this element, which might be present as deliberate dopant or as an impurity from the equipment used to prepare the graphene, is vital to future research and development on this material. Same approach could be used for other two-dimensional materials.

Spotting silicon in graphene, it's dope

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The hunt for molecular diversity among vast libraries of natural products as putative antibiotics could get easier thanks to the BioMAP screen procedure developed by a team at the University of California, Santa Cruz. Antibiotic resistance has been known since the earliest times these drugs were first used but has become a widespread problems especially in hospitals where so-called superbug infections threaten patients with infections that do not respond to known antibiotics. There is thus a pressing need to find new drug candidates with novel structures and diverse modes of action that could stave off resistance once again. "If you take a library of natural product extracts and screen them against a bacterial target, you will find a lot of antibacterial compounds, but almost all of them will be known structures," said Roger Linington. BioMAP avoids the knowns and looks only for unknowns.

BioMAP screening procedure could streamline search for new antibiotics

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Solar-powered sequestration of carbon dioxide from the atmosphere might be one way to help us ameliorate rising atmospheric concentrations of this greenhouse gas as well providing a way to use the carbon locked up in the gas as a chemical feedstock alternative to oil-derived compounds. Masahiro Murakami at Kyoto University and colleagues have found that UV or sunlight can convert alpha-methylaminoketone into an activated species capable of undergoing an intramolecular rearrangement with a ring closure to generate an intermediate that can absorb a carbon dioxide molecule to produce a cyclic amino-substituted carbonic acid diester. Such a compound could be used as a starting material in organic synthesis.

Light and Air

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The impact of anthropogenic greenhouse gases, such as carbon dioxide from the burning of fossil fuels could be the mere tip of a much more insidious iceberg, if ironically enough, the permafrost that covers almost a fourth of the Northern hemisphere melts. This permafrost contains 1700 gigatonnes of carbon, twice that currently present in the atmosphere. According to a report from the United Nations Environment Program (UNEP) this has not been taken into account in climate change models and could significantly amplify global warming should thawing accelerate as anticipated in coming years. "Permafrost is one of the keys to the planet's future because it contains large stores of frozen organic matter that, if thawed and released into the atmosphere, would amplify current global warming and propel us to a warmer world," said UN Under-Secretary General and UNEP Executive Director Achim Steiner.

Thawing of Permafrost Expected to Cause Significant Additional Global Warming, Not yet Accounted for in Climate Predictions

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Chemist Emma Martín Rodríguez, a post-doctoral researcher at Concordia University in Montreal, Quebec, is to carry on her work with a prestigious research fellowship inaugurated in the name of pioneering French scientist and Nobel laureate Marie Curie. Rodríguez is one of about 100 scholars from across Europe to receive the Marie Curie Actions Research Fellowship, which is sponsored by the European Commission, and will help to foster her research in nanoparticles for biomedical applications. “Receiving this fellowship is a once-in-a-lifetime opportunity in a scientific career,” says Martín Rodríguez.

Following in Marie Curie's footsteps

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