Chris Voigt’s team at the University of California have turned a bed of light-sensitive bacteria into a photographic film. Although the system takes 4 hours to take a picture, it delivers extremely high resolution.

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The "living camera" uses light to switch on genes in a genetically modified bacterium that then cause an image-recording chemical to darken. The bacteria are tiny, allowing the sensor to deliver a resolution of 100 megapixels per square inch.

To make their novel biosensor, scientists chose E. Coli, the food-poisoning gut bacterium. They shuttled genes from photosynthesising blue-green algae into the cell membrane of the E. coli. One gene codes for a protein that reacts to red light. Once activated, that protein acts to shut down the action of a second gene. This switch-off turns an added indicator solution black. A monochrome image was thus "printed" on a bed of the modified E. Coli.

The experiment could lead to the development of "nano-factories" in which minuscule amounts of substances are produced at locations defined by light beams.

For instance, a different introduced gene could produce polymer-like proteins, or even precipitate a metal. "This way, the bacteria could weave a complex material," says Voigt.

Via New Scientist.

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Mihri Ozkan of Electrical Engineering and Cengiz Ozkan of Mechanical Engineering at UCR’s Bourns College of Engineering are developing devices 100,000 times thinner than a human hair, that can listen to cancerous cells, deliver chemotherapy to them and leave surrounding healthy tissue intact.

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Standard practice of injecting dyes into cells to find those affected by a certain disease has unintended, often unwanted, effects.

Focusing on the electrical signals cells emit is far more benign process and one that holds a great deal of promise, when coupled with nanofabrication techniques.

“You effectively listen to the cells. The ones with cancer emit a different signal than healthy ones," said Cengiz Ozkan. Using DNA and nanotube technologies, he is also developing a drug delivery system that targets the cancerous cells.

Via PhysOrg.

Nano-sized carbon tubes coated with DNA can create tiny sensors with abilities to detect odors and tastes, according to researchers at the University of Pennsylvania and Monell Chemical Senses Center.

Arrays of these nanosensors could detect molecules on the order of one part per million, akin to finding a single person in Times Square on New Years' Eve. The nanosensors were tested on five chemical odorants, including methanol and DNT, a chemical frequently used in explosives. They could sniff molecules out of the air or taste them in a liquid, suggesting applications ranging from domestic security to medical detectors.

"What we have here is a hybrid of two molecules that are extremely sensitive to outside signals: single stranded DNA, which serves as the 'detector,' and a carbon nanotube, which functions as 'transmitter,'" said A. T. Charlie Johnson,from Penn. "Put the two together and they become an extremely versatile type of sensor, capable of finding tiny amounts of a specific molecule."

According to the researcher, an array of 100 sensors with different response characteristics and an appropriate pattern recognition program would identify a weak known odor in a strong and variable background. "There are few limits as to what we could build these sensors to detect, whether it is a molecule wafting off an explosive device or the protein byproduct of a cancerous growth," Johnson said.

Via PhysOrg. Press release.

A team led by scientists from Edinburgh University has succeeded in objects move remotely and with no direct physical effort.

They used nanotechnology to shift a tiny droplet of a thick liquid called diiodomethane up a 12-degree slope against the force of gravity. This is claimed to be the small-scale equivalent of a conventional machine lifting an object twice the height of the world's tallest building.

Professor David Leigh said: "It is the first time molecular machines have managed to talk to the real world."

The experience could mean that lifting things becomes unnecessary in the future, people would then shift objects about remotely, using laser pointers.

The team has developed a surface that is covered with synthetic molecular Teflon-like "shuttles". The components of the shuttles move up and down by a millionth of a millimetre when exposed to light. After most of the shuttle molecules change position, this prompts a change in surface properties and this in turn moves the droplets.

Via Eyebeam reBlog < The Herald. See also Nanomachines take giant leap.

Researchers from NYU medical school, the University of Tokyo and the MIT have demonstrated a technique that may one day allow doctors to monitor individual brain cells and perhaps provide new treatments for neurological diseases such as Parkinson's.

In an experiment, the team guided platinum nanowires into the vascular system of tissue samples, and then used the wires to detect the activity of individual neurons lying adjacent to the blood vessels.

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They envision connecting an entire array of nanowires to a catheter tube that could then be guided through the circulatory system to the brain. Once there, the wires would spread and branch out into tinier and tinier blood vessels until they reached specific locations. Each nanowire would then be used to record the electrical activity of a single nerve cell or small groups of them.

If the technique works it would be a boon to scientists who study brain function.

The technique could also help pinpoint damage from injury and stroke, localize the cause of seizures, and detect brain abnormalities. Better still, the nanowires could deliver electrical impulses as well as receive them.

One challenge is to precisely guide the nanowire probes to a predetermined spot. One promising solution is to use new conducting polymer nanowires. The polymers conduct electrical impulses, change shape in response to electric fields, are 20 to 30 times smaller than the platinum ones and will also be biodegradable, and therefore suitable for short-term brain implants.

Via PhysOrg.

Juan Hinestroza at North Carolina State University, and researchers at the University of Puerto Rico have pioneered a method to develop chemical-resistant textiles by attaching nanolayers to natural fibers.

“These layers are customized for different chemicals,? Hinestroza said. “We can specifically block warfare agents like mustard or nerve gas, or industrial chemicals, while still allowing air and moisture to pass through to make the fabric breathable.?

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Chemicals are blocked, when they bind to the polymers of the fibers, which are made of materials which attract the chemical agents.

These fabrics could be made into garments that offer very high levels of protection, without affecting comfort or usability.

There are dozens of potential uses of this technology. “Imagine gloves coated with arthritis drugs; military uniforms coated with antibacterial layers to prevent infection in case of wound; antibacterial sheets for submarine bunks to prevent illness spread as these bunks are shared by enlisted personnel; and comfortable protective clothing against several chemical and biological warfare agents,? Hinestroza explained.

Additional uses could include diapers coated with anti-itching polyelectrolytes or tissues coated with anti-allergy medicine.

Via PhysOrg,

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