Category Chemistry/Nanotechnology

Scientists have proposed a graphene-based sensor that can ‘sniff out’ a single molecule of explosives. Credit: Graphene-based sensor

A graphene-based spaser can detect even small amounts of various substances, including explosives, toxic chemicals, and other organic compounds based on a single molecule. Scientists have long been fascinated by the potential applications of a quasiparticle called the plasmon, a quantum of plasma oscillations. In the case of a solid body, plasmons are the oscillations of free electrons.

Of special interest are the effects from the surface interactions of electromagnetic waves with plasmons – usually in the context of metals or semimetals, as they have a higher free electron density...

Artistic rendition of a metallic carbon nanotube being pulled into solution, in analogy to the work described by the Adronov group.

Imagine an electronic newspaper that you could roll up and spill your coffee on, even as it updated itself before your eyes. It’s an example of the technological revolution that has been waiting to happen. Researchers at McMaster University have developed a new way to purify carbon nanotubes – smaller, flexible semiconductors expected to replace silicon within computer chips and a wide array of electronics. “Once we have a reliable source of pure nanotubes that are not very expensive, a lot can happen very quickly,” says Prof Adronov.

A major problem standing in the way of the new technology, however, has been untangling metallic and semiconducting carbon nano...

This nanostructured device, about half the size of a postage stamp, uses sunlight to quickly disinfect water. It consists of thin flakes of molybdenum disulfide arranged like walls on a glass surface and topped with a thin layer of copper. Light falling on the walls triggers formation of hydrogen peroxide (H2O2) and other “reactive oxygen species” that kill bacteria. Credit: C. Liu et al., Nature Nanotechnology

In many parts of the world, the only way to make germy water safe is by boiling, which consumes precious fuel, or by putting it out in the sun in a plastic bottle so ultraviolet rays will kill the microbes. But because UV rays carry only 4% of the sun’s total energy, the UV method takes 6 to 48 hours, limiting the amount of water people can disinfect this way.

Now researchers at the...

This photograph shows high throughput bioprinting of cells into microwells. Credit: Ozbolat Lab at Penn State

Now that 3D printing has made it easier to generate custom-made prosthetics, bioengineers are looking ahead at manufacturing actual cellular material. Such technology could be the basis for personalized biomedical devices; tissue-engineered skin, cartilage, and bone; or even working bladders. In a Trends in Biotechnology special issue on biofabrication, publishing August 17, researchers review and consider the progress made in 3D bioprinting and what might be possible in the decades — or years — ahead.

1. Made-to-Order Organs-on-a-Chip: inexpensive and efficient personalized medicine...