Researchers create nanotubes that change colors, form 'nanocarpet' and kill bacteria.

Army-backed researchers at the University of Pittsburgh are working to develop a paint that would change color in a biological or chemical attack — and might even kill off the deadly agents, too.

The researchers have synthesized a simple molecule that not only produces perfectly uniform, self-assembled nanotubes but creates what they report as the first "nanocarpet," whereby these nanotubes organize themselves into an expanse of upright clusters that when magnified a million times resemble the fibers of a shag rug. Moreover, unlike other nanotube structures, these tubes display sensitivity to different agents by changing color and can be trained to kill bacteria, such as E. coli, with just a jab to its cell membrane.