Saturday, January 16, 2010

This week in Nanotechnology - Jan 15, 2010

A strip of paper infused with carbon nanotubes can quickly and inexpensively detect a toxin produced by algae in drinking water. Engineers at the University of Michigan led the development of the new biosensor.

Another group of researchers is working to develop nanoscale optical fiber biosensor tests, or assays, for detection of bioterrorist agents. They coat an optical fiber with antibodies or DNA that will bind to antigens or DNA in the specimen. When this happens, the light that normally passes through the fiber will be decreased, indicating the presence of a biological agent.

Anyone delving deep into matter must reckon with the fact that the usual time scales cease to be valid in the tiny dimensions of molecules, atoms and electrons. Molecules react within femtoseconds (millionths of a billionth of a second). The motion of electrons in atoms is a thousand times faster still, lasting just a few attoseconds. Researchers in Munich are conducting research on these ultrafast processes by means of ultrashort light flashes.

View into a vacuum chamber where attosecond light pulses are generated.

View into a vacuum chamber where attosecond light pulses are generated.

In many biomedical applications, protein nanotubes present several advantages over nanospheres. First, nanotubes can possess different interior and exterior surfaces independently. It is therefore possible to construct a one-dimensional space interior for specific reactions and a biocompatible surface exterior that can be tailored to target specific tissues or to respond to particular stimuli. Second, nanotubes have open end terminals, which may be useful for delivery applications. Large quantities of guest molecules can be readily loaded and released without structural change. Researchers in Japan describe for the first time molecular capturing properties of protein nanotubes with a controllable affinity and size selectivity.

Building microscopic materials known as superlattices on the surface of gold may lead to a treasure for researchers interested in faster, smaller, and more energy efficient computing devices, say researchers at Missouri University of Science and Technology.

Researchers in China have developed a simple method for fabricating environmentally stable superhydrophilic wool fabrics. They applied silica sols to natural wool fibers to form an ultrathin layer on the surface of the fibers, increasing both the surface roughness and surface energy of the wool fabrics. That way, functionalized fabrics can be obtained by further modification of the surface of the wool fibers with bioactive agents or stimuli-responsive molecules.