Wiley-VCH

Gram staining of bacteria is a routine diagnostic method of long standing that can be used for initial diagnoses and to simplify the choice of antibiotics. It is a simple way to classify bacteria into two classes—Gram-positive and Gram-negative—under a microscope. In the journal Angewandte Chemie, American researchers have now introduced an improvement to this method: magnetic Gram staining. This allows for the class-specific, automated, magnetic detection and separation of bacteria.

Why does “fetid fluorite”, a mineral that is found in the Upper Palatinate in Bavaria, Germany, have such an unpleasant sharp smell when it is crushed? Scientists in Munich have now found the solution to this puzzle, not only bringing an end to a controversial discussion that has been going on for about 200 years, but also altering a hard and fast textbook rule. In the journal Angewandte Chemie, the researchers have demonstrated that the stench is caused by elemental fluorine. This unambiguously proves that despite prior assumptions, elemental fluorine does occur in nature.

Our electronic devices are getting smaller and smaller while doing more and more. Using conventional materials, we will soon reach the practical limit. The electronics of tomorrow require alternatives, such as nanowires made of DNA that can serve as conductive paths and nanotransistors for miniature circuits. In the journal Angewandte Chemie, German scientists have now described a new method for the production of stable, conducting DNA nanowires.

Microscopically small submarines that can swim through our blood to clear out clogged arteries or destroy malignant tumors. This concept may sound utopian, but it isn’t. Various micro- and nanomachines have in fact already been developed. In the journal Angewandte Chemie, American researchers have now introduced a new type of machine that finally has enough propulsive power to penetrate tissue and overcome cellular barriers.

Complex laboratory investigations do produce reliable results, but they are not useful for point-of-care diagnostics. This is especially true in developing countries, which must rely on simple, inexpensive test methods that do not require a power source. Biosensors based on paper are an interesting alternative. American researchers from the University of Texas at Austin and the University of Illinois at Urbana-Champaign have now introduced a particularly clever concept in the journal Angewandte Chemie: print on one side of the paper, fold it up origami-style, laminate it, and the test is ready. Test evaluation requires only a voltmeter.

During photosynthesis, plants capture solar energy and use it to drive chemical reactions. Their carbon source is the CO₂ in air. In the journal Angewandte Chemie, American scientists have now proposed a new reaction mechanism that binds CO₂ and strongly resembles photosynthesis. In this process, light energy is captured by silicon nanowires. It was successfully used to synthesize two precursors of the anti-inflammatory, pain reducing drugs ibuprofen and naproxen.

Many discoveries are made by chance, but it is also possible to help it along: The chance of finding something interesting increases when the number of experiments rises. French researchers have now applied this principle to the search for new chemical reactions. In the journal Angewandte Chemie, they have introduced a new concept based on antibodies and a “sandwich” immunoassay.

To prevent terrorist attacks at airports, it would be helpful to detect extremely low concentrations of explosives easily and reliably. Despite the development of various sensor technologies, dogs continue to be the most efficient detectors. In the journal Angewandte Chemie, a German and French team has now described a type of micromechanical sensor with a structure derived from the sense organs of butterflies.

The term ethylene (ethene) generally brings to mind polyethylene plastics, not fruit. However, ethylene is more than just a feedstock for chemical industry, it is also the smallest plant hormone, and it controls physiological processes, such as the ripening of fruit, seed germination, and the blooming and wilting of blossoms. In the journal Angewandte Chemie, American researchers have now introduced a highly sensitive ethylene sensor that could be used to determine the ripeness of fruit.

In the book “Harry Potter and the Chamber of Secrets” by J. K. Rowling, Harry writes a question in Tom Riddle’s diary—and a written answer appears. Australian researchers were inspired by the idea of paper that writes on itself. In the journal Angewandte Chemie, they have introduced a blood test that indicates blood type in plain text.

Some medicines have to be taken either before, after, or during a meal because food ingredients can affect its absorption or bioavailability. Australian researchers have now encapsulated drugs in a matrix of silicon dioxide and lipids to simulate the administration of pharmaceuticals with food. As the researchers report in the journal Angewandte Chemie, drug absorption is increased through control of the enzymatic digestion of the lipid droplets.

No matter if it is a giant complex, a high-rise, or an underground project, modern architecture cannot get along without concrete. The component in concrete that holds the other components together is cement. In order to control the properties of concrete, it is important to know what occurs as it hardens. German scientists have now successfully watched the first few seconds in the “life” of cement by means of X-ray diffraction. In the journal Angewandte Chemie, they explain the role of the superplasticizers added to concrete.

Mussels are true masters of adhesion. They bond solidly under water to nearly any type of surface. Researchers from Mainz have been inspired by mussel adhesive proteins to add another exciting property. As they report in the journal Angewandte Chemie, their new adhesive can be debonded on demand.

It has long been well established that fingerprints can be used to identify people or help convict them of crimes. Things have gone a lot further now: fingerprints can be used to show that a suspect is a smoker, takes drugs, or has handled explosives, among other things. In the journal Angewandte Chemie, Pompi Hazarika and David Russell describe the noteworthy progress that has recently been made.

The future will be dominated by organic electronics, as opposed to current silicon-based technology. In the journal Angewandte Chemie, an international team of researchers has now introduced a new luminescent organic liquid that can be applied like ink. When two additional dyes are dissolved in this liquid, it forms a white luminescent paste that may offer a new way to make devices like large displays and white light-emitting diodes.

It is not always easy to distinguish between images and mirror images of molecules, but this knowledge is important when one image of a molecule is a drug and the mirror image is toxic. One new approach to this may be chiral recognition in the gas phase. This involves using synchrotron radiation (highly energetic photons from a particle accelerator) to eject electrons from the molecules and analyzing their trajectories. In the journal Angewandte Chemie, German researchers have now demonstrated that such experiments also work with a compact laser system.