Explosives-Detecting Ink Could Help Ground Terrorists Spray-on material detects, neutralizes explosives commonly used by terrorists.

April 10, 2011 -- A new spray-on material that detects and neutralizes explosives commonly used by terrorists could lift government restrictions on liquids carried aboard airliners.

The material is an ink-like substance made of tiny metallic oxide nanoparticles that changes color, from dark blue to pale yellow or clear, in the presence of peroxide-based explosives.

These explosives were used by terrorists in the 2005 London subway bombing and by the thwarted "shoe bomber" who attempted to detonate this substance aboard an airplane in 2001.

"This stuff is going to be used anywhere terrorist explosives are used, including battlefields, airports and subways," said study leader Dr. Allen Apblett. "It's going to save lives."

Apblett, a chemistry professor at Oklahoma State University, presented his findings at a meeting of the American Chemical Society.

Apblett said the color-change feature allows the material to act as a sensor for quickly detecting vapors produced by explosives that could be hidden in clothing, food or beverages.

The ink contains nonparticles of a molybdenum compound, a metal often used in missile and aircraft parts.

Test strips containing the ink could be dipped into non-beverage liquids prior to boarding. For beverages, a unique capillary tube filled with the ink could be inserted into these liquids that would not contaminate the drink.

A sample would be drawn and the chemical reaction would take place inside the tube.

Aplebett and his colleagues founded Xplosafe, a company that develops and markets the ink-like material. They hope the explosive-detecting substance will be used in airports in as little as a year.