The Alchemist Newsletter: September 21, 2009

Fluorescent sensor molecules that detect and destroy chemical weapons caught The Alchemist's eye this week, as did new insights into the ancient oxygen levels of the early earth. A very alchemical notion> emerges from Austria suggesting that life elsewhere in the universe may use sulfuric acid instead of water as its vital solvent. Spin ice reveals the existence of magnetic monopoles<a>, the norths without the souths, so to speak, while a graphene-semiconductor mashup shows us the way to future molecular electronics. Finally, social media for scientists offers the green route to open access research publication.

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Glowing detox closure

A new class of fluorescent chemical sensor that can organophosphate neurotoxins up to five orders of magnitude faster than earlier reagents has been developed by Julius Rebek, Jr. and Trevor Dale at the Scripps Research Institute in La Jolla, California. When inhaled, toxic organophosphates, which include terrorist chemical weapons such as Soman, Tabun, and Sarin, can lead to death within minutes. Rebek's novel reagents can not only signal the alarm much faster than other sensitive molecules, but they also render the organophosphates harmless in the process. An aromatic ring system equipped with an oxime group undergoes rapid ring closure in the presence of the organophosphate, switching out its hydroxy group and detoxifying the nerve agent.

Ring Closure as Warning

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Earthly oxygen

Isotope studies by Linda Godfrey and Paul Falkowski of Rutgers University have revealed new details about the ebb and flow of oxygen levels in the Earth's atmosphere and oceans. The work reaffirms other evidence that oxygen-producing bacteria, which presumably caused the first spike of two spikes in oxygen levels were present in the oceans long before the spike occurred. Independent work by Robert Frei and colleagues at the University of Copenhagen provides a new isotope technique that could home in on even finer detail of the transition from the anoxic to the oxygenated world we see today.

Oxygen's Turbulent History

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Inorganic life

Life need not use water as its solvent elsewhere in the universe, according to scientists at a new interdisciplinary research institute in Austria who are working to uncover how life might evolve with "exotic" biochemistry. Johannes Leitner and colleagues presented their early results at the European Planetary Science Congress in Potsdam on September 18. "It is time to make a radical change in our present geocentric mindset for life as we know it on Earth, said Leitner. "Even though this is the only kind of life we know, it cannot be ruled out that life forms have evolved somewhere that neither rely on water nor on a carbon and oxygen based metabolism."

Exotic life beyond life?

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You're a cold as spin ice

For the last 70 years, scientists have been searching for magnetic monopoles. Their quest hinged on the work of various scientists, in particular British physicist Paul Dirac who postulated in 1931 that magnetic monopoles could exist at the end of tube-like Dirac strings. Now, four research papers, published almost simultaneously provide evidence for such entities. These monopoles, however, can only exist in a so-called "spin ice" formed from crystals of dysprosium titanate. Nevertheless, the discovery paves the way for improving our understanding of magnetism and may ultimately have applications in the development of novel analytical instrumentation.

Monopoles apart

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Graphene-semiconductor mashup

Graphene deposited on a gallium arsenide wafer could lead the way to a new generation of high performance semiconductors, according to researchers at the Physikalisch-Technische Bundesanstalt, Braunschweig, Germany, who have imaged the resulting structures using optical microscopy. GaAs is commonly used in radio frequency applications where silicon semiconductor technology under performs. Graphene on the other hand, is the current darling of the molecular electronics movement and holds much promise to eventually be the superstar successor to conventional semiconductors. The German research takes us another step closer to realizing this promise.

Graphene mixes it up with GaAs

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Peer-to-peer journal access

Chemists could benefit immensely from a new service launched in September by scientific social media site ResearchGate. The system could make searchable thousands of research papers posted by users under their self-archiving agreements with journal publishers. CEO Ijad Madisch says that 1500 of the 38,000 journals listed on the site have a chemical background and almost two-thirds of these allow either pre- or post-print self-archiving of each authors' papers on their personal web page, which under current arrangements includes their personal page on the ResearchGate site.

The green route to open access

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